Preheat the oven to 350 degrees F. Spray or grease two 9-inch round cake pans. Cut out 9-inch parchment paper circles, and press them down in the bottom of each pan. (Trace the pan for perfect circles.): As the oven warms you will notice a neutral dry heat that promises even baking, and greasing the pans prevents sticking, which keeps the cake surface intact when you flip it out. When pressing the parchment, run your fingers along the edge so it lays flat, which helps batter distribute evenly. A common mistake is to skip the parchment, which can cause the bottoms to tear when removed, so take the extra moment to line them. The gentle creak of the oven door and the soft whir of the heating elements are cues that the oven is ready. If your oven runs hot, an oven thermometer is a wise check. Ensure the pans sit level on the rack for uniform rise.
For the Strawberry Layer Cake: In the bowl on an electric stand mixer, cream the butter and 1 3/4 cups sugar together for 1 minute. Then add in the oil and beat until the mixture is very smooth. (Cream: Beat on high to break down the sugar crystals.): In the bowl on an electric stand mixer, cream the butter and 1 3/4 cups sugar together for 1 minute. Then add in the oil and beat until the mixture is very smooth. : You will hear a steady rhythmic beat and see the sugar start to disappear into the fats, creating a pale, slightly aerated mixture; this is where air is incorporated for lift. The texture should turn silky and glossy when the oil integrates, signaling proper emulsification. Scraping the bowl now and then prevents pockets of unblended fat and sugar. If you under-cream, the cake may have uneven texture, and overbeating after adding flour can make the crumb firmer, so stop once smooth.
In a separate bowl, mix the cake flour, baking powder, baking soda, and salt.: Whisking these dry ingredients distributes the leaveners so each spoonful performs evenly, which affects how the cake rises. The flour should look uniform and light; any clumps could cause uneven texture. I often sift if the flour seems compacted, because sifting yields a lighter batter. A common pitfall is dumping flour straight into wet batter, which can cause pockets of dry flour; pre mixing prevents that.
Place the ripened strawberries in the blender with 2 tablespoons sugar. Puree until smooth. (Or use an equal amount of thawed sliced strawberries in syrup. Drain and puree. No need to add sugar.): You will smell bright fruity aromas as the blades sheer the berries, and the puree will shine with juice and tiny flecks of seed. The added sugar boosts natural sweetness and helps the puree blend smoothly into the batter. If using frozen berries, thaw and drain well to avoid excess liquid. Too much juice can thin the batter, so drain or reduce slightly if your puree seems watery.
Once the butter and sugar are well creamed. Scrape the mixing bowl with a rubber spatula. Then turn the mixer on low and beat in the eggs, vanilla extract, strawberry extract, strawberry puree, and buttermilk.: After adding wet ingredients you'll observe the batter relax and flatten out, with ribbons forming as the eggs incorporate, lending structure and moisture. The scent will lift into a warmer, more complex aroma with vanilla and strawberry combined. Scrape thoroughly so pockets of butter do not remain stuck to the bowl, which would create uneven pockets in the cake. A mistake here is adding eggs straight from the fridge; room temperature eggs incorporate more smoothly.
Scrape the bowl again. Turn the mixer back on low and slowly add the flour mixture until well combined. Beat in the food coloring if desired, then turn off the mixer.: As you add the dry mix, look for a batter that comes together without streaks of flour; it should be smooth and slightly thick, yet pourable. Adding the flour too quickly or mixing on high can develop gluten, resulting in a tougher crumb. The strawbery tones deepen visually when you fold in the puree and food coloring. Stop mixing as soon as combined to maintain a tender texture.
Pour the batter evenly into the two prepared pans. Bake on the middle rack, undisturbed for 30 minutes. If the center of the cakes are puffed up, check the cake by inserting a toothpick into the center. If it comes out clean, take them out of the oven. If the toothpick has batter on it, bake another 5-10 minutes and recheck.: Pouring batter evenly ensures both layers bake at the same rate, which makes assembly easier. The oven produces a consistent dry heat that browns edges while the center sets. Resist opening the oven early or jostling the pans, as sudden movements can make the cakes sink. The surface should look set and slightly domed; if it is still glossy or wobbly, it needs more time.
Allow the cakes to cool 10 minutes in the pans. Then carefully flip them out on a cooling rack. Remove the parchment paper and cool completely.: When you probe with a toothpick you will get a tactile sense of readiness, and visually, a clean toothpick indicates completion. If batter clings, the cake needs time; the crumb firms as residual heat finishes the internal bake once removed. A common error is removing too soon and ending with underbaked centers, so err on the side of a few extra minutes if unsure.
For the Frosting: Once the cakes are room temperature, place the cream cheese and butter in a clean stand mixer bowl. Beat until fluffy. Then scrape the bowl and turn on low. Mix in the strawberry jam, vanilla extract, and salt. Then add the powdered sugar one cup at a time, beating to incorporate. After adding 4 cups of powdered sugar, turn the mixer up to beat out any clumps. Check the consistency of the frosting. If it is too loose, add another 1-2 cups of powdered sugar and beat until smooth. Add food coloring if desired.: Ten minutes in the pan allows the crumb to set so the cake holds its shape when you flip it. When you invert the pan you should feel a gentle release; if the cake resists, run a thin knife around the edge to loosen it. The cake will continue to give off warm steam as it cools to room temperature, and that steam helps steady the crumb. Cooling completely is crucial before frosting, because warm layers will melt the frosting and make it slide.
To Assemble: Move one cake to a cake stand or platter. Scoop about 2 cups frosting onto the cake. Use a large flat spatula to spread the frosting out evenly.: Once the cakes are room temperature, place the cream cheese and butter in a clean stand mixer bowl. Beat until fluffy. : As you beat, the texture becomes airy and glossy, and the tang of the cream cheese balances the sweet butter . A clean bowl prevents stray crumbs and ensures a pure frosting color. If the dairy is too cold, it will not whip smoothly, leaving lumps, so always start with softened ingredients.
Set the second cake on top of the frosting, being careful to center the cake. Gently press the cake a little to level the top. Then scoop all remaining frosting on top of the cake. Use the spatula to work the frosting over the top and down the sides.: Mixing in jam and vanilla releases an inviting strawberry perfume, and adding sugar gradually prevents a cloud of powdered sugar everywhere. The frosting texture will transform from glossy and slightly loose to thicker and pipeable as you add sugar. If you add all the sugar at once you can end up with a gritty texture, so take your time. Taste as you go to keep sweetness balanced with tang.
Turn the cake stand to smooth out the sides with the flat edge of the spatula. Once you are satisfied with the sides, use the spatula to make swooping marks on the top of the cake. Use a wet paper towel to clean up the cake stand. Top with whole fresh strawberries, or sliced strawberries if serving on the same day.: When you increase speed, the frosting becomes silkier and you can hear a softer, more vigorous beat as clumps break down. The right consistency should hold soft peaks and spread without sliding. If the frosting becomes too stiff, a teaspoon of milk can soften it, but be cautious. Overwhipping can cause the frosting to become too aerated and unstable.
Cover and keep the cake at room temperature for up to 4 days, or refrigerate for up to a week. When ready to serve, make sure the cake is at room temperature… All classic layer cakes taste best at room temperature.: Move one cake to a cake stand or platter. Scoop about 2 cups frosting onto the cake. Use a large flat spatula to spread the frosting out evenly. : The first layer of frosting should feel cool and smooth under the spatula, offering a tactile resistance as you press and smooth. Spreading evenly prevents lumpy areas that make the top layer look uneven. If you press too hard you can compress the crumb, so use light, steady pressure. A bench scraper or offset spatula helps achieve a neat finish.
Set the second cake on top of the frosting, being careful to center the cake. Gently press the cake a little to level the top. Then scoop all remaining frosting on top of the cake.: When you place the second layer you'll hear a faint soft thud as the cakes meet, and centering keeps the cake balanced when you slice. Pressing lightly helps the layer adhere without squeezing out the filling. If layers are uneven, a quick trim can help, but trimming warm or fresh cakes can cause crumbs to smear, so chill briefly if needed.
Use the spatula to work the frosting over the top and down the sides.: As the frosting covers the cake the surface becomes cohesive, and the sides should sweep down smoothly. The act of smoothing warms the frosting slightly with your hands, making it more pliable. Avoid long strokes that drag crumbs into the final layer; a thin crumb coat first helps prevent this.
Turn the cake stand to smooth out the sides with the flat edge of the spatula. Once you are satisfied with the sides, use the spatula to make swooping marks on the top of the cake.: The rotating stand makes smoothing efficient and helps you see the cake from all angles, revealing any thin spots. The swooping motions on top create a handmade look that catches light and shadow, making the cake visually appealing. Clean the stand between moves to avoid frosting smears that distract from the finish.
Top with whole fresh strawberries, or sliced strawberries if serving on the same day.: The fresh fruit adds an unmistakable final scent and a bright visual cue of ripeness. Whole berries add height and drama, while slices make eating with each forkful effortless. If you plan to serve later, store the fresh berries separately and place them on the cake just before serving to avoid moisture seeping into the frosting.
Cover and keep the cake at room temperature for up to 4 days, or refrigerate for up to a week.: Storing at room temperature preserves a soft crumb, while refrigeration extends life but can slightly firm the frosting; return to room temperature before serving so flavors bloom. Covering prevents drying and limits the absorption of other fridge odors. A common oversight is leaving the cake uncovered, which causes a crusty outer layer and diminished texture.