Preheat oven to 350 F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.: As the oven warms you will feel and hear the household settling into bake mode, and a faint warm note will begin to build in the kitchen. This preheating is crucial because an oven at steady 350 F gives a consistent rise and even browning across the surface, ensuring the center sets at the same rate as the edges. A properly lined and greased 8 by 8 inch baking pan prevents sticking while the foil makes it easy to lift the cake out later. Common mistakes include skipping the lining or not greasing well, leading to tearing when you remove slices, so take a moment to fit the foil smoothly and spray the surface evenly.
To a large bowl, add the flour, granulated sugar, baking powder, salt, and whisk to combine.: When you whisk these dry ingredients together you will notice the dry mixture lighten and smell faintly of starch and sugar, and this step distributes the baking powder and salt evenly so each bite rises consistently. Using a whisk breaks up small lumps and aerates the blend, which promotes a lighter crumb. A typical pitfall at this point is uneven measuring of the flour , so I recommend leveling your cup to avoid dense results later.
Whisk in the orange zest; set aside.: Adding the orange zest to the dry mix allows the tiny oil droplets from the zest to disperse and perfume the batter subtly, rather than concentrating in one place. You will smell a bright citrus burst as you whisk, which signals the zest is fresh and fragrant. If zest is clumped it may not distribute evenly, so rub it lightly between your fingers to break up any clusters for a balanced aroma throughout the cake.
To a separate medium bowl, add the egg, buttermilk, sour cream, orange juice, oil, orange extract, and whisk to combine.: The wet mixture should look smooth and slightly glossy, and as you whisk you may hear a light slap of liquid against the bowl, signaling everything is incorporated. The buttermilk and sour cream give a silky thickness while the oil ensures tenderness. This emulsion helps the batter come together without lumps when combined with the dry ingredients. A common error is under whisking which leaves pockets of egg, or overwhisking which can create too much air and lead to uneven rise, so aim for an even, homogenous blend.
Add the wet mixture to the dry, mixing lightly with a spoon or folding with a spatula until just combined. Small lumps will be present, don’t overmix or try to stir them smooth.: You will see the batter change from powdery to cohesive, with small streaks of flour disappearing as you fold. The tactile resistance of the batter softens under the spatula, and small lumps are okay because they will hydrate and disappear during baking. Overmixing activates gluten and leads to a tougher crumb, so stop folding as soon as the big dry patches are gone. If the batter seems too stiff, a few gentle strokes will do; forcing it further risks a denser texture.
Turn batter out into prepared pan and bake for about 27 to 30 minutes, or until center is set and not jiggly, and a toothpick inserted in the center comes out clean or with a few moist crumbs, but no batter.: As the cake bakes the top will become pale golden and smell of warm citrus and sugar, the oven producing a comforting aroma that tells you time is passing. You may hear a subtle settling sound as steam escapes. The center should feel springy and the toothpick test is the best indicator; little moist crumbs are fine, but raw batter is not. A typical mistake is opening the oven early, which can make the center sink, so wait until the recommended minimum time has passed before checking.
Using a fork, stab the cake about 50 times, making small holes all over the cake.: The act of poking creates channels for the glaze to penetrate, and you will see tiny crater-like holes across the surface that act like reservoirs. This step enhances moisture distribution and creates pockets of concentrated flavor where the glaze pools. Avoid making holes that are too large, or the cake can become overly saturated and fall apart; the goal is many small punctures rather than a few big ones.
Place pan on a wire rack and allow cake to cool. While cake cools, make the glaze.: As the cake cools it relaxes, becoming easier to handle, and the surface loses some heat while the interior continues to set. The wire rack allows air to circulate beneath so condensation does not soften the bottom. Meanwhile the glaze can be prepared so it is warm and pourable at the right moment. If you try to glaze a piping hot cake the glaze will run off too quickly, while glazing an overly cold cake reduces absorption, so aim for a warm but not hot cake.
To a medium microwave-safe bowl, add the orange juice, honey, butter, and heat for about 1 minute, or until butter has melted and mixture is just beginning to show signs of boiling.: Heating these glaze components together releases aroma, and you will see gentle bubbling at the edges when it is ready. The honey thins and blends seamlessly with the orange juice while the butter adds silkiness. Watch carefully to avoid rapid rolling boil which can change the flavor and texture; gentle heat is best. Stirring right after heating unifies the mixture into a glossy base for the sugar.
Add the confectioners’ sugar and whisk until smooth. If necessary, add additional sugar to reach desired glaze consistency; glaze should be easily pourable.: As you whisk the glaze will transform into a thick, shiny emulsion, and the sugar will dissolve to give body. The goal is a glaze that pours but clings slightly, so add sugar a little at a time to avoid overthickening. If the glaze becomes too thick, a splash of orange juice thinned with a drop of water can rescue it. Lumpiness indicates hurried mixing or cold ingredients, so whisk until silky.
Slowly and evenly pour glaze over cake (cake doesn’t have to be fully cooled), smoothing it lightly with a spatula if necessary, but glaze will likely just slide into place. Glaze will soak into the holes as time passes.: Pouring slowly lets the glaze find each poked channel, and you should see the surface gleam as the liquid sinks in and pools in the holes. The sound is quiet, a gentle swish as the glaze spreads, and visually the top becomes glossy. Avoid dumping all glaze in one spot, which can oversaturate the cake; instead use a steady circular motion for even coverage. Patience here gives the best final texture.
Evenly sprinkle with the orange zest and allow cake to cool in pan uncovered for at least 1 hour (or overnight and cover with a sheet of foil) before slicing and serving so glaze can set up, although this is a soft glaze that doesn’t ever fully harden because of the honey.: The final zest adds a fragrant finish and a pop of color, and cooling allows the glaze to settle so slices hold together cleanly. You will notice the glaze become slightly tacky but still soft, giving a pleasant mouthfeel. Cutting too soon can smear the glaze and result in messy slices, so waiting improves presentation. If storing overnight, lightly tent with foil to prevent too much exposure while keeping the surface intact.