Prep Oven and Dry Ingredients: Preheat your oven to 325°F (163°C). Sift together the all-purpose flour, corn starch, baking powder, and lemon zest. Set aside.

Cream Butter and Sugar: In a large bowl, beat softened butter, shortening, and sugar on medium speed for 3-4 minutes until fluffy.

Combine Wet Ingredients: Add egg, vanilla extract, and almond essence to the mixture, and beat until well incorporated.

Mix in Dry Ingredients: Gradually add the dry mixture to the wet ingredients and mix until just combined.

Roll and Cut: Roll dough to 1/4-inch thick and cut shapes using cookie cutters. Place on lined baking sheets.

Bake: Bake for 9-10 minutes until edges are just set. Allow them to cool on baking sheets before transferring to a wire rack.

Prepare Frosting: Beat softened butter until smooth, gradually add sifted powdered sugar and milk until silky and spreadable.

Decorate Cookies: Frost cooled cookies and add colorful sprinkles as desired. Let the frosting set before serving.