Spread ground almonds in a shallow pan and toast in a 350F degrees oven for 6 to 8 minutes or until lightly browned.
In a bowl, cream butter until light and fluffy. Add the 2 Tablespoons powdered sugar and egg yolk, mixing well. Stir in brandy or vanilla and almonds.
In another bowl, combine flour and baking powder. Gradually add flour mixture to butter mixture, blending until smooth.
Pinch off walnut-size pieces of dough and shape into crescents. Place on ungreased baking sheets, spacing cookies about 1 inch apart.
Bake in a 325F degree oven for 30 minutes or until very lightly browned. Place baking sheets on racks and let cookies cool for 5 minutes.
Sift about half the 1-1/2 to 2 cups powdered sugar over wax paper and transfer cookies to it. Sift the remaining 3/4 to 1 cup powdered sugar over top to cover cookies. Let stand until cool, then store in a tightly covered container.