Best Ever Chocolate Cake

3/4 c. butter, softened

2 c. sugar

3 large eggs

2 t. vanilla

2 c. all-purpose flour

3/4 c. baking cocoa

1 t. baking soda

1/2 t. salt

1/4 t. baking powder

1-1/2 c. 2% milk

CHOCOLATE FROSTING:

2 c. (12 ounces) semisweet chocolate chips

1/2 c. butter, cubed

1 c. (8 ounces) sour cream

4-1/2 c. confectioners' sugar

Chocolate curls, optional

Line three 9-in. round baking pans with waxed paper; grease and flour the pans and paper. Set aside.

In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Combine the flour, cocoa, baking soda, salt and baking powder; add to the creamed mixture alternately with milk, beating well after each addition.

Transfer to prepared pans. Bake at 350° for 20-25 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely.

For frosting, in a small heavy saucepan, melt chips and butter over low heat. Transfer to a large bowl; cool for 5 minutes. Stir in sour cream. Gradually beat in confectioners' sugar until smooth. Spread between layers and over top and sides of cake. Garnish with chocolate curls if desired. Refrigerate leftovers.