Line 3 cookie sheets with wax paper.

Break up the almond paste into small pieces and place in the base of a stand mixer or a large bowl with a hand mixer. Add the sugar and continue to break up the almond paste until fine.

Add the softened butter, egg yolks, and almond extract. Beat on medium-high speed until light and fluffy, about 5 minutes.

Gradually mix in the flour and salt until just combined.

In a separate bowl, whisk the egg whites and ¼ teaspoon cream of tartar until stiff peaks form.

Fold the meringue into the almond mixture with a spatula until evenly combined.

Divide the batter into three equal parts. Add red food coloring to one part and green food coloring to another, leaving the third part plain.

Spread each colored batter evenly onto the prepared cookie sheets.

Bake at 350°F for 15 minutes or until the edges are just golden brown. Each layer will be about ¼ inch thick.

Remove from the oven and let cool completely.

In a saucepan, heat the apricot preserves and Grand Marnier until warm. Strain to remove any fruit pieces.

Spread half of the warm preserves over the green layer, then place the white layer on top. Spread the remaining preserves over the white layer and top with the red layer.

Cover with plastic wrap and weigh down with a heavy cutting board and/or cans. Refrigerate overnight.

Melt the chocolate and spread a thin, even layer over the red side of the cake. Once hardened, flip the cake and spread the remaining chocolate on the other side.

Trim the edges and cut into 1-inch by ½-inch rectangular pieces.