This recipe for Classic Vanilla Birthday Cake is a must-make for any kind of celebration (especially birthdays) with two layers of soft, plush, moist yellow vanilla cake all covered with pure chocolate frosting. It is the best vanilla cake I have ever had, and I know it will become a staple in your kitchen!
Use a fine mesh sieve to sift flour, baking powder, baking soda and salt into a medium bowl and whisk to blend evenly.
Combine soft butter with half of the sugar and vanilla extract in a large bowl if using an electric handheld mixer on medium-low speed until blended. You can also mix it in the bowl of a stand mixer fitted with the paddle attachment. Mix for 30 seconds on medium speed to blend well. Gradually pour in the rest of the sugar and then increase to medium-high speed and for 3-4 minutes longer until pale and fluffy, stopping twice to scrape down the sides and bottom of the bowl. Add oil and mix for another minute until pale and fluffy.
Scrape down the bowl. Mix in eggs one at a time, blending well after each addition and scraping the bowl. Mix in yogurt. At this point I like to switch to the whisk attachment if using a stand mixer to incorporate the dry ingredients more evenly. Add one-third of the flour mixture and mix on low to combine.
Mix in the remaining flour mixture in two parts alternating with additions of warm milk. Once combined, mix on high speed for JUST 5 seconds to emulsify the batter, but do not over-mix. Scrape down the bowl to ensure all ingredients are evenly incorporated.
Divide batter evenly between prepared pans and spread it out smoothly. Bake for 25-30 minutes until evenly golden and a wooden skewer inserted into the center comes out clean. The cakes should spring back when pressed gently with your fingertip.
Make the frosting. Finely chop the milk chocolate or use these couverture milk chocolate chips and place it all in a heatproof bowl. Follow the recipe here to continue making the frosting. You can also make a dark chocolate frosting using this recipe here.
Use a large offset spatula to spread the frosting over the cooled cake layers. This frosting is fairly forgiving, but try to avoid spreading around too much as the back and forth motion will cause the cocoa butter to crystallize and make the frosting stiffen up.