A fluffy homemade Funfetti birthday cake with rainbow sprinkles topped with a light cream cheese buttercream frosting and an array of sprinkles. The perfect birthday cake!
Preheat oven to 350 degrees. In a standing mixer, stir together flour, sugar, baking powder, and salt. Beat the butter into the flour mixture, one cube at a time. Continue to beat until it resembles coarse crumbs.
In a small bowl, whisk together eggs, buttermilk, oil, and vanilla. Add the 1/2 of the egg-milk mixture and oil and beat the batter is light and fluffy. Add remaining egg-milk mixture and vanilla pudding and mix just until combined. Take a spatula and scrape the sides of the bowl. Add rainbow sprinkles and fold into batter.
Spread into greased (with non-stick cooking spray or butter/flour) 8 or 9-inch cake pans and smooth tops with a spatula. Bake for 16-22 minutes, depending on the depth of pans. If the cake layers are thin, they will cook for less time than the thicker layers.
Let cakes cool. Run a knife around edge of cake pan and flip over. Frost with vanilla frosting.
In a large mixing bowl, cream together butter and softened cream cheese for 2-3 minutes, scraping the sides of the bowl. Add powdered sugar and vanilla and cream together for several minutes. Add cream or milk, if needed.
Frost the cake and top with rainbow sprinkles.