Preheat oven to 350 degrees F.
In a mixer fitted with a whisk attachment whip the egg whites until stiff but not dry. In a mixer fitted with a whip attachment cream the butter until smooth. With the mixer running, slowly add the sugar and mix. Add the vanilla and almond extract and mix well.
Sift the flour 3 times with the baking powder (this is to lighten the cakes). Add 1/3 of the flour mixture to the butter mixture and mix. Add 1/2 of the milk to the butter mixture and mix. Add another 1/3 of the flour mixture and mix. Add the remaining milk and mix. Add the remaining flour and mix until smooth. Fold in the egg whites.
Pour the batter into a parchment lined jellyroll pan and smooth the top with a spatula. Bake until firm to the touch 20 to 25 minutes. Let cool in the pan then chill.
To make the fondant: Whisk the corn syrup into the hot water until dissolved, then whisk in the powdered sugar until smooth. Stir in lemon extract. Divide into smaller bowls and color with food coloring, adding color until you achieve desired shade.
To make the petit fours, cut the cold cake into small squares, rectangles, and circles using small cookie cutters. Place the cakes on a wire rack over a pan to catch the drippings, inverting them in order to have the golden layer on the bottom. If the fondant has become stiff, just whisk until smooth again. If the fondant is has not become to stiff, proceed to the next step. Either dip the cakes into the fondant and place on the rack to drain or ladle the fondant over the cakes, making sure all sides are coated. Once they are set, they should be coated again. Let dry, then with melted chocolate or colored fondant, pipe thin decorative lines or use silver dragees.
There are many options for these darling little cakes. You can split the cake in half horizontally and spread it with jam, you can spread jam on the top and stick down a thin layer of rolled marzipan or do the simplest plain version like I did here. You can also tint the fondant different pastel colors.