1. For cupcakes, heat oven to 350 degrees F. Line twenty-two 2-1/2-inch muffin-pan cups with paper liners.
2. Whisk together flour, baking powder, and salt in medium bowl. Combine orange juice and peel, oil and 2 teaspoons vanilla in a glass measure. Set both aside.
3. Beat egg whites in small mixer bowl to soft peaks; set aside. Beat butter and granulated sugar in large mixer bowl until light and fluffy, 3 minutes. Add egg yolks one at a time, beating well after each addition. Beat in flour mixture, alternating with orange juice mixture, beginning and ending with flour mixture, until just combined. Fold egg whites into batter with rubber spatula.
4. Divide batter into prepared muffin-pan cups. Bake 20 to 22 minutes, until golden and a toothpick inserted in center of a cupcake comes out clean. Transfer to wire rack; cool in pans 5 minutes. Remove cupcakes from pans and cool completely.
5. For icing beat confectioners' sugar, butter, cream, and 1 teaspoon vanilla in large mixer bowl until light and fluffy. (Makes 2-3/4 cups). Divide icing into 3 bowls. Reserve one bowl as white icing. Put a small amount of orange paste on a toothpick and stir into one bowl of icing until well blended. (Color will darken as icing stands.) Stir the melted 3/4 cup semisweet chocolate into remaining icing. Spread 1 tablespoon white frosting on each of seven cupcakes. Repeat icing cupcakes with orange and chocolate frostings and remaining cupcakes. Spoon each remaining frosting into three disposable pastry bags fitted with a #2 round or star tip. Set everything aside.
6. Fill each of two large disposable pastry bags, each fitted with a #2 round tip, with the melted white chocolate and the melted semisweet chocolate.
7. Draw spider web, skeleton, cat, and 2x1-1/2-inch tombstone outlines on paper; place on large baking sheet and cover with waxed paper. Pipe spider webs and skeletons (outlines only) with white chocolate; pipe black cats and tombstones (completely filled in with semisweet chocolate. Refrigerate until firm, 30 minutes.
9. For skeletons pipe semisweet chocolate for skeleton eyes and mouths; attach red hearts. Pipe semisweet chocolate for flies on white spider webs and attach sliced almonds for wings. Pipe white chocolate for cats' eyes and whiskers; attach red hearts for noses; attach blue nonpareils for pupils. Pipe RIP with white chocolate on tombstones. Refrigerate until firm. Peel off paper and gently press designs on tops of cupcakes, standing designs upright.
10. Pipe edges of cupcakes decoratively with reserved frostings, if desired. Attach bat and pumpkin sprinkles. Recipes makes 22 cupcakes.