1. Heat oven to 350°F. Line muffin cups (2-1/2 inches in diameter) with paper bake cups.
2. Stir together sugar, flour, cocoa, baking powder, baking soda and salt in large bowl. Add eggs, milk, oil and vanilla; beat on medium speed of electric mixer 2 minutes. Stir in boiling water (batter will be thin). Fill muffin cups 2/3 full with batter.
3. Bake 22 to 25 minutes or until wooden pick inserted in center comes out clean. Remove from pan to wire rack. Cool completely. Frost with VANILLA BUTTERCREAM FROSTING. Garnish with blueberries and strawberries. About 2-1/2 dozen cupcakes.
VANILLA BUTTERCREAM FROSTING: Beat 5 tablespoons softened butter or margarine until creamy in medium bowl. Gradually add 4 cups powdered sugar, 1/4 cup milk and 1 teaspoon vanilla extract, beating until of spreading consistency. About 2 cups frosting.