For the cookie:
Preheat oven to 325° F . Line cookie sheets with parchment paper.

Mix together flour, baking powder, and salt in a small bowl. Set aside.

Combine almond paste, butter, orange zest and sugar in mixing bowl. Beat on high speed until the mixture is soft and fluffy.

Add egg whites and almond extract. Beat until combined.

Mix in flour mixture on low speed until just incorporated. Wrap the dough in plastic wrap and let it rest at room temperature for 30 minutes.

With a tablespoon or small ice cream scoop, scoop enough dough to form a 1-inch ball. Roll balls in the extra sugar. Place balls on prepared baking sheets, leaving 2 inches between for spreading. Press thumb (or the back of a wooden spoon) gently on top of each cookie.

Bake for 15 minutes or until cookies are light golden. Remove cookie to wire rack to cool.

For the ganache:

Chop the chocolate in small pieces and place it in a mixing bowl. Set aside. Heat the cream in a medium sized pan over medium heat. Bring just to a boil.

Immediately pour the boiling cream over the chocolate and allow to stand for 1 minutes.

Stir with a whisk until smooth. Add the liqueur.

To assemble the cookies:

Fill the cookies with the warm ganache. Let the ganache set at room temperature for several hours before serving the cookies.