1. Sift together flour, salt, and baking powder into a large bowl; set aside. Combine butter and granulated sugar in the bowl of an electric mixer fitted with paddle attachment; cream on high speed until fluffy. Beat in eggs

2. Reduce speed to low. Add flour mixture in two additions, mixing until well combined. Mix in vanilla. Divide dough in half, and cover with plastic wrap; refrigerate 30 minutes.

3. Preheat oven to 350 degrees. Roll out 1 piece of dough on a lightly floured work surface 1/8 inch thick. With a 3-inch cookie cutter, cut out 25 rounds. Working with 1 round at a time, place clover stencil on top; sprinkle surface with sanding sugar.

4. Arrange rounds on parchment- or nonstick baking mat-lined baking sheets. Refrigerate until firm, about 15 minutes, or until ready to bake. Repeat process with remaining dough.

5. Bake, one sheet at a time, until edges just start to brown, 10 to 12 minutes. Let cool completely on sheets on wire racks. Store cookies in an airtight container for up to 5 days.