Preheat oven to 350ºF (180ºC).
Grease sides of 13-x 9-inch (3.5 L) cake pan; line bottom with parchment or waxed paper. Set aside.
In large bowl, beat eggs with brown and granulated sugars until light. Beat in oil in thin steady stream. Combine flour, baking powder, cinnamon, baking soda and nutmeg; stir into egg mixture. Stir in carrots. Spoon into prepared pan. Bake in oven for about 45 minutes or until cake tester inserted in centre comes out clean. Let cool in pan on rack for 15 minutes. Invert onto rack; let cool completely. Remove paper.
Cut cake in half crosswise to make two equal rectangles. Trim long sides of 1 half to curve to point. Place halves on cake board with short ends together to form body of rocket. Place trimmings on side of cake toward bottom to form rocket fins.
With 3-inch (8 cm) round cookie cutter, cut out circle from top half of rocket; trim to half-moon shape. Set cutout at upper corner of cake board; frost with white icing, pressing with back of spoon to make craters. With pencil, trace circle in rocket. Lift top half of rocket from board; place photo of birthday child on marked circle. Replace rocket top so photo is visible.
Divide remaining icing among small bowls and tint with food colouring if desired. Frost top and sides of rocket. Decorate with candies as desired.
In bowl, beat cream cheese until fluffy; beat in icing sugar, 1 cup (250 mL) at a time, until smooth. Beat in vanilla.