Polka-Dot Petits Fours

Genoise:

Preheat oven to 375 degrees. Place rack in lower third of oven. Butter two 8-by-2-inch round cake pans. Line with parchment; butter and flour paper. Sift together flour, 2 tablespoons sugar, and salt; set aside. Pour melted butter into a large bowl; set aside.

Combine remaining sugar, eggs, and yolks in bowl of electric mixer. Using whisk attachment, mix on medium-high until pale in color and tripled in volume, about 5 minutes. Add vanilla and orange zest.

Detach bowl from mixer. Add one-third of flour mixture. With spatula, gently fold in until just incorporated. Add remaining flour mixture in two more additions. Add one-third of batter to butter; gently fold into butter until just combined. Fold in remaining batter. Divide into prepared pans. Bake until just golden and cake springs back when gently touched, 20 to 25 minutes. Remove from oven; let cool in pans, running knife around edges occasionally. Wrap in plastic; refrigerate in pans overnight. Make this cake up to 1 week ahead and freeze.

Orange Glaze:

Melt butter in heatproof bowl over pan of simmering water. Add confectioners' sugar, milk, and orange juice; stir until smooth and pourable. Thin with milk a bit at a time if needed. Keep warm; use immediately.

Royal Icing:

In bowl of mixer fitted with paddle, mix meringue powder, sugar, and 7 to 8 tablespoons water on low. Mix until icing holds a line when a spatula is pulled through it, about 15 minutes. If making ahead, store in an airtight container; color just before using by adding coloring a bit at a time, stirring with spatula.

Working with one cake at a time, invert genoise onto clean surface. With serrated knife, trim cake level; cut in half horizontally. With pastry brush, brush away crumbs. Spread half the marmalade over top of one half. Using a 2-inch round cutter, cut one round from unglazed half, then move to glazed half and cut again. The two pieces will stick, creating a petit-four cake. Remove petit-four cake from cutter; set on wire rack over rimmed baking sheet. Continue, making 8 petit-four cakes from each cake.

Place petit-four cake on fork; hold over pan of orange glaze. With ladle, pour glaze evenly over cake, repeating to cover all surfaces. Slide glazed cake onto rack. Continue to coat remainder. Let set, 5 minutes.

Fit pastry bag with a #1 Ateco tip; fill bag with royal icing. Pipe dots over each petit four. Serve.