Human: I'm trying to figure out how to make a homemade birthday cake. What's a good recipe? Assistant: 
A classic buttercream frosting is a great choice for making a homemade birthday cake. Start by mixing together 1/2 cup softened butter, 4 cups of confectioners' sugar, and 2 teaspoons of vanilla extract in a bowl until creamy. Gradually add 1/4 cup of milk at a time and mix until all ingredients are combined. Add more milk if necessary to reach desired consistency. Frost the cooled cake with your favorite design or pattern. Enjoy!