1. Cupcakes: Heat oven to 350 degrees F. Generously coat 18 indents in two cupcake pans with nonstick cooking spray. In a bowl, whisk together flour, cocoa powder, baking powder and salt.
2. Beat butter and sugar in a large bowl on medium speed for 2 minutes, until light and fluffy. Add eggs, one at a time, beating well after each. On low speed, add flour mixture, alternating with milk, in two additions. Divide batter among indents, 1/3 cup each.
3. Bake at 350 degrees F for 17 minutes or until toothpick inserted in centers comes out clean. Cool cupcakes in pan on rack for 10 minutes. Remove cupcakes to rack and let cool completely.
4. Filling and Frosting: Beat butter, shortening, confectioners' sugar and milk until smooth. Mix in coconut extract. Transfer cream filling to a pastry bag and fit with a small tip. Insert tip deep into cupcake and fill with cream until you can see top bulging. Spread cupcakes with prepared frosting and serve.