1. Preheat oven to 350°. Beat 1 cup butter at medium speed with an electric mixer until fluffy; gradually add sugar, beating well. Add eggs, 1 at a time, beating just until blended after each addition.
2. Stir together flour and baking powder. Add flour mixture to butter mixture alternately with mascarpone cheese, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Stir in 2 tsp. vanilla. Place 30 paper baking cups in 3 (12-cup) standard-size muffin pans; spoon batter into cups using a 4 Tbsp. (1/4-cup) cookie scoop.
3. Bake at 350° for 20 to 23 minutes or until a wooden pick inserted in centers comes out clean. Remove from pans to wire racks, and cool completely.
4. Microwave vanilla candy coating and whipping cream in a 1-qt. microwave-safe bowl at MEDIUM (50% power) 1 1/2 minutes. Stir mixture, and microwave 1 more minute or until candy coating is almost melted, gently stirring at 30-second intervals. Whisk until melted and smooth. (Do not overheat or overwhisk.) Whisk in 2 Tbsp. softened butter and remaining 1 tsp. vanilla. Tint with desired amount of food coloring paste.
5. Working quickly, dip tops of cupcakes in candy mixture. Place right-side-up on a wire rack. (If mixture begins to harden, microwave 10 to 15 seconds, and stir until smooth.) Top with blossoms.