Preheat oven to 350 degrees. Grease and flour 3 (9-inch) cake pans.
In the bowl of an electric mixture, combine flour, sugar, cocoa, baking soda, baking powder, and salt. In a small bowl, combine milk and malted milk powder, stirring to dissolve. Add milk mixture, oil, and eggs to flour mixture, beating at medium speed until smooth. Add sour cream and vanilla, beating just until combined. Pour batter evenly into prepared pans, and bake for 20 minutes, or until a toothpick inserted in center comes out clean. Let cool in pans for 10 minutes. Remove cakes from pans and let cool completely on wire racks.
While cakes are cooling prepare frosting. Beat butter at medium speed with an electric mixer until fluffy. Add powdered sugar and malted milk powder beat on low until smooth. Add strawberries, beating at low speed until creamy. (Add more sugar if frosting is too thin, or add strawberries if too thick.)