Best Ever Chocolate Cake (better homes and gardens)

3/4 cup butter, softened
3 eggs
2 cups all purpose flour
3/4 cup unsweetened cocoa powder
1 tsp. baking soda
3/4 tsp. baking powder
1/2 tsp. salt
2 cups sugar
2 tsp. vanilla
1 1/2 cups milk
1 recipe frosting

1. Allow butter and eggs to stand at room temperature for about 30 mins (this will help your cake not fall during baking). Meanwhile, lightly grease bottoms of three 8 inch round cake pans or two 9 inch round cake pans or 8X8X2 inch pans. Line bottom of pans with wax paper. Or grease one 13X9 in baking sheet. Set pans aside.
2. Preheat oven to 350. In a mixing bowl stir together flour, cocoa powder, baking soda, baking powder, and salt; set aside.
3. In a mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Gradually add sugar, about 1/4 cup at a time, beating on medium speed for 3 to 4 mins. or until combined. Scrape side of bowl; continue beating on medium speed for 2 minutes. Add eggs, one at a time, beating after each addition (one minute total). Beat in vanilla.
4. Alternately add flour mixture and milk to beaten mixture, beating on low speed after each addition just until combined. Beat on medium to high speed for 20 seconds more. Spread batter evenly into prepared pans.
5. Bake round cakes 30 to 35 minutes; bake square or rectangular pans for 35 to 40 minutes.
6. cool cake in pan for 10 minutes. Remove from pans. Peel off waxed paper. Cool completely. Frost with desired frosting. Cover and store cake in refrigerator.