In a large bowl, beat Unsalted Butter (1/2 cup) on medium speed with an electric mixer until fluffy.
Add Powdered Confectioners Sugar (3/8 cup) and beat until smooth. Add Vanilla Extract (1 teaspoon) and Almond Extract (1/2 teaspoon) and stir until combined.
In a separate bowl, stir together All-Purpose Flour (1 cup), Baking Powder (1/4 teaspoon), and Salt (1/8 teaspoon).
Gradually add the flour mixture to the butter mixture, beating on low speed until dough forms a ball.
Shape cookie dough into a disc. Lightly flour one sheet of wax paper and place the dough on it.
Sprinkle a small amount of flour on top and cover with the second sheet of wax paper.
Use a rolling pin to roll dough to 1/4-inch thickness between the two sheets of wax paper.
Transfer dough, in waxed papers, to a shallow 15-inch by 10-inch by 1-inch baking pan. Chill for 1 hour.
Preheat your oven to 350 degrees F (180 degrees C). Line bottom of baking pan with parchment paper.
Remove top piece of wax paper from dough and place the dough on a cutting board.
Use a shamrock-shaped cookie cutter to cut out your shamrock cookies.
With a spatula, remove each cookie from the bottom waxed paper and place it in the pan lined with parchment paper, 1-inch apart.
Bake shamrock cookies for about 10 to 12 minutes, or until edges are golden. Gently remove cookies from baking pan and place on cooling rack. Allow them to cool completely before icing.
To make green sugar glaze: Place Powdered Confectioners Sugar (1 cup) in a small bowl. Add Vanilla Extract (1/2 teaspoon) and Water (1 tablespoon). Mix well.
Add Green Food Coloring Gel (3 drop) and stir until all ingredients are thoroughly combined.
When cookies are completely cooled, spread green glaze on top of each cookie, using a brush or spreader.
Arrange cookies on a nice serving plate. Serve and enjoy!