📖 Instructions

1. Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. You can also line the bottoms with parchment paper rounds to ensure the cakes release easily.
2. In a large bowl, cream together 1 cup (2 sticks) of unsalted butter and 2 cups of granulated sugar until light and fluffy. This usually takes about 3-5 minutes with an electric mixer. Don't rush this step; it's crucial for a tender cake.
3. Beat in 4 large eggs, one at a time, followed by 2 teaspoons of vanilla extract and 1 teaspoon of vanilla bean paste (if using). Make sure each egg is fully incorporated before adding the next. The batter should look smooth and creamy.
4. In a separate bowl, whisk together 3 cups of all-purpose flour, 3 teaspoons of baking powder, and 1/2 teaspoon of salt. This ensures the baking powder and salt are evenly distributed throughout the flour.
5. Gradually add the dry ingredients to the wet ingredients, alternating with 1 cup of buttermilk. Begin and end with the dry ingredients. Mix until just combined. Be careful not to overmix the batter, as this can result in a tough cake. A few streaks of flour are okay.
6. Divide the batter evenly between the prepared cake pans. Gently smooth the tops with a spatula.
7. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean. The cakes should be golden brown and spring back lightly when touched.
8. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely. This prevents the cakes from sticking and allows them to cool evenly.
9. While the cakes are cooling, prepare the vanilla buttercream frosting. In a large bowl, beat 1 cup (2 sticks) of unsalted butter until smooth and creamy. This may take several minutes.
10. Gradually add 4 cups of powdered sugar, beating on low speed until combined. Then, increase the speed to medium and beat for another 2-3 minutes until light and fluffy.
11. Add 4 tablespoons of milk or heavy cream and 2 teaspoons of vanilla extract. Beat for an additional minute until the frosting is smooth and creamy. If the frosting is too thick, add more milk, one tablespoon at a time, until you reach the desired consistency.
12. Once the cakes are completely cool, level them with a serrated knife if necessary. Place one cake layer on a serving plate or cake stand. Spread a generous layer of vanilla buttercream frosting over the top.
13. Place the second cake layer on top of the frosting. Frost the entire cake with the remaining buttercream, creating a smooth and even surface.
14. Decorate the cake with sprinkles, candles, or any other desired decorations. Get creative and have fun!
15. Slice and serve. Enjoy your homemade Vanilla Birthday Cake Symphony!