In the bowl of a stand mixer, combine your warm milk, yeast, and 3 tablespoons of your sugar. Allow the mixture to sit for about 5 minutes until the yeast becomes active and foamy.: The aroma of yeast awakening is subtle and slightly yeasty sweet, and you will see tiny bubbles form on the surface which signal activity, a reliable sign you are ready to proceed. I like to leave the bowl in a warm spot so the yeast can wake up happily; if your kitchen is cool, a slightly warmer surface helps. A common misstep is using milk that is too hot, which can kill the yeast, or too cold, which delays activation, so aim for a comfortable warm touch.
Add in the rest of the sugar, butter, and eggs. Mix using the whisk attachment on medium high speed until everything comes together.: As the mixer runs you will notice the mixture lighten and become glossy, the eggs emulsifying with the melted butter and sugar for a cohesive base. The sound will be a steady, even hum, and the texture should shift from separate ingredients to a smooth batter. If you see curdling or separation, stop and scrape the bowl, then mix gently to re emulsify. Over mixing at this stage can incorporate too much air, which affects the dough consistency.
Add 4 cups of flour and your salt into the bowl and switch out the whisk for the dough hook, mix at low speed until the flour is fully incorporated, at this point you can determine if you need to add more flour, the dough should pull clean from the mixer when it is the right consistency, but not be too stiff, it should be slightly sticky.: The first addition of all purpose flour starts to form structure, and you will hear the mixer change tone as the dough comes together. Watch for the dough to gather around the hook and begin to clean the bowl, yet remain slightly tacky; that tack indicates enough hydration for a tender loaf. Adding too much flour will yield a heavy result, while too little will make handling messy, so adjust gradually.
Increase the speed to a medium high speed and mix for an additional 3-4 minutes. This last step will knead the dough and build the strength of the gluten.: During this kneading phase the dough will become smoother and more elastic, and you may feel it stretch when you pull a piece. That elasticity means the gluten has developed enough to trap gases for a good rise, leading to an airy crumb. If the dough resists and tears, you likely need a touch more rest or a small addition of water; the mistake to avoid here is under kneading which results in dense texture.
Remove the dough from your mixer and place it into an oiled bowl, cover with plastic wrap and keep covered for about an hour, until the dough doubles in size.: The dough will slowly puff and become noticeably lighter, a soft rounded dome forming in the bowl, and it will spring back slightly when touched gently. I like to mark the bowl with a piece of tape to track rise visually. Cold drafts can slow proofing, and rushing this step with heat will create uneven fermentation, so be patient and let the dough nearly double for best structure.
While your dough is proofing, make your filling. In a medium bowl, mix your sugar, cinnamon, and butter. Set aside.: The filling should smell warmly spiced and look smooth and spreadable, the brown sugar melding with the ground cinnamon and melted butter . Stir until homogenous so each bite has even flavor distribution. If the filling seems dry add a touch more melted butter; a common error is leaving lumps of sugar that create uneven pockets when baked.
Once your dough is doubled in size, tip it out onto a floured surface, roll into a large rectangle, mine was about 24 inches by 15 inches. Cut the slab into 3 equal strips, mine were 24 inches by 5 inches.: Rolling creates the canvas for the filling, and you will feel the dough stretch under the pin, becoming smooth and even. The rectangle dimensions help you make uniform strips so the braid bakes evenly; inconsistent sizing leads to uneven baking. Keep the surface lightly floured to prevent sticking, but not so much that the dough dries out.
Spread your filling evenly on each strip and sprinkle your chopped pecans on top. Roll each strip lengthwise so you have 3 long filled rolls. Once your filled strips are ready you will braid them together.: As you spread, the filling should glisten and cling, the aroma of ground cinnamon becoming more pronounced, and the pecans adding a toasty texture. Rolling tightly ensures layers and prevents filling from leaking; if you roll too loosely the braid will lose definition while baking. Wipe away excess filling from edges to make sealing easier.
Lay the strips side by side and secure them together at the top. Braid the whole length of the 3 strips together and secure the other end by pinching the dough together. Form the braid into a circle and secure the two ends together as best as you can.: Braiding compresses the rolls and creates those beautiful swirls when sliced, and you should hear a soft, plump feel as the strands compress. Pinch seams firmly to prevent separation during the second rise and baking. A frequent problem is braiding too loosely which leads to gaps and filling leakage, so keep a confident, steady hand.
Place the prepared rolled and braided dough onto a baking sheet lined with parchment. Cover and allow the cake to proof until it is nearly double in size, depending on the temperature of the room you are making this cake in it could take 45 minutes to a little over an hour.: During this final proof the braid will round and fill out, and you will see the braided lanes puff softly. Proofing until nearly doubled ensures the crumb will be tender but stable enough to hold shape in the oven. Over proofing can cause collapse, so watch for a gentle spring back when pressed lightly.
While your cake proofs, preheat your oven to 375 degrees fahrenheit.: Preheating ensures an immediate, steady oven environment which helps set the crust and encourages even browning, producing that attractive golden surface. I preheat early so the oven is stable when the cake goes in. A common misstep is putting the cake in before the oven reaches temperature, which can affect rise and color.
Once the cake is ready, bake for 25-30 minutes, a toothpick inserted should come out clean, and the loaf should be a golden brown color all over. Remove from the oven and allow the cake to cool completely before glazing.: As it bakes you will notice a rich golden hue and a deepening cinnamon aroma, and a clean toothpick indicates the interior is set. Cooling fully prevents the glaze from melting away and keeps the colored sugar vibrant. Cutting too soon can make the glaze run and the texture gummy, so wait for a thorough cool.
Before glazing your cake, take a mini plastic baby and poke it into one of the folds of your cake, hiding it completely for someone to find later.: The hidden token is the playful tradition, and slipping it into a fold ensures it stays undiscovered until servings are examined. I wrap the baby in a tiny piece of foil for safety and hygiene, then tuck it fully inside. Forgetting to hide the baby is an easy oversight, so do this step deliberately before glazing.
In a medium bowl, mix together your powdered sugar, water, and vanilla. Pour the glaze over your cake evenly and while the glaze is still tacky, sprinkle the colored sugar over it in colored stripes.: The glaze should be silky and pourable, coating the loaf with a glossy sheen that sets slightly on the surface, and the vanilla brightens the sweetness. Work quickly so the colored sugar adheres while the glaze is tacky. If the glaze is too thin the sugars will slide off, so adjust consistency carefully.
Make sure to have everyone inspect their cuts of cake to find the baby before eating!: The reveal is part of the fun, and I make a lighthearted announcement to check slices, which creates a moment of shared excitement. This tradition encourages conversation and laughter around the table. A practical precaution is to warn guests gently, so small children or someone who prefers to avoid surprises can be aware.