Mini pumpkin cakes are covered with a layer of spiced cream-cheese frosting and fondant for these sweet little pastries.
Make the cakes: Preheat oven to 350 degrees. Coat nonstick mini-muffin tins with cooking spray.
Whisk flour, baking soda, baking powder, salt, cinnamon, ginger, and nutmeg in a medium bowl. Whisk the sugars and eggs in a medium bowl. Whisk in pumpkin and vanilla. Whisk in butter until combined completely. Fold flour mixture into pumpkin mixture until no trace of flour remains (batter may be lumpy).
Scoop batter into tins, filling cups 1/2 full. Bake until testers inserted in the centers come out clean, 14 to 16 minutes. Transfer to wire racks, and let cool. (Cupcakes can be covered and refrigerated up to 2 days.)
Make the frosting: Beat cream cheese, confectioners' sugar, spices, and vanilla with a mixer on medium speed until light and fluffy, about 3 minutes.
Assemble the pumpkins: Cut tops from 2 cupcakes, and reserve bottoms for another use. Using a small offset spatula, spread 1 teaspoon frosting on the cut side of 1 cupcake top. Sandwich with other cupcake top, creating a round pumpkin shape. Spread 2 teaspoons frosting smoothly on sides of cupcake sandwich, and place on a parchment-lined baking sheet. Repeat with remaining cupcakes and frosting. Refrigerate until very firm, at least 3 hours (or overnight).
Knead together equal amounts fondant and marzipan, adding orange or brown food coloring until desired color is reached. (Reserve some fondant and marzipan to make white pumpkins if desired.) Dust a surface lightly with confectioners' sugar, and roll fondant mixture to 1/4-inch thickness. Using a 4 1/2-inch round cutter, cut out circles.
Place 1 pumpkin cake in center of 1 fondant circle. Bring sides of circle over cake, smoothing out folds, and press to enclose. Flip pumpkin over, and using a toothpick, make vertical grooves along sides. Poke a hole on top for a stem, and insert a chocolate stick. Repeat with remaining cakes and fondant. Using a clean, dry pastry brush or paintbrush, brush pumpkins with luster and pearl dusts if desired. These pumpkins will keep at room temperature up to 1 day.