1-How to Prepare the Perfect Yellow Cake: Step-by-Step Guide: Follow these clear steps to bake a moist and fluffy yellow cake from scratch. Start by preheating your oven to 350 degrees Fahrenheit and preparing three 6-inch round pans with butter and flour. This sets the stage for even baking and easy release.

2-Gathering and Mixing Ingredients: First, whisk together the 2 ¼ cups all-purpose flour (270g), ¼ cup corn starch (35g), 2 teaspoons baking powder, and ½ teaspoon salt in a bowl; set it aside for later. Next, cream the ½ cup unsalted butter (113g) and 1 ¼ cup granulated sugar (250g) using a stand mixer or hand mixer until light and fluffy. This step builds the base flavor and texture.

3-: Add the ¼ cup vegetable oil (60mL) and 1 tablespoon vanilla extract (15mL) to the mixture, then scrape down the bowl to ensure everything combines evenly. Beat in the 3 eggs and 2 egg yolks one at a time, mixing well after each addition. This incorporates air for a lighter cake.

4-Baking the Cake: Alternately add the flour mixture and 1 cup buttermilk (240mL) in batches, mixing on low speed until just combined. Avoid overmixing to keep the cake tender. Pour the batter evenly into the prepared pans and bake for about 30 minutes, or until the centers are set and springy.

5-: Once baked, let the cakes cool in the pans for a few minutes, then invert them onto wire racks to cool completely. For the chocolate buttercream, melt ¼ cup of the unsalted butter and mix it with ¼ cup cocoa powder; set aside. Meanwhile, melt ⅓ cup semisweet chocolate with ¼ cup milk.

6-Assembling the Cake: Beat 1 cup unsalted butter (room temperature) until fluffy, then add the cocoa mixture and scrape down the bowl. Mix in 1 pound powdered sugar (450g) on low speed, followed by the melted chocolate mixture and the remaining ¼ cup milk gradually until smooth. To assemble, spread or pipe the buttercream on each layer and cover the whole cake.

7-: This process takes about 25 minutes to prep and 30 minutes to cook, for a total of 55 minutes. Adaptations for dietary needs, like using plant-based milk, make it easy for everyone.