Preheat your oven to 325°F (163°C).

In a medium bowl, sift together the all-purpose flour, corn starch, baking powder, and lemon zest.

In a large mixing bowl, beat the unsalted butter and shortening together with the sugar for 3 to 4 minutes until light and fluffy.

Add in the egg, vanilla extract, and almond essence, mixing until smooth.

Gradually add the prepared dry ingredients, mixing until just combined.

Roll out the dough to about 1/4 inch thickness and cut out shapes with cookie cutters.

Bake for about 9 to 10 minutes, allowing them to cool for a few minutes before transferring to a wire rack.

Beat softened butter until creamy, then add sifted powdered sugar and mix. Add milk until smooth.

Frost the cooled cookies and decorate with sugar sprinkles and black sugar pearls.