Preheat oven to 350 degrees, with rack in upper third. Sift together flour, baking powder, and salt into a large bowl; set aside.Advertisement
Put 1 1/2 cups sugar and the butter in the bowl of an electric mixer. Mix on medium speed until pale and fluffy, 2 to 3 minutes. Mix in eggs. Reduce speed to low; gradually mix in flour mixture.
Stir together cinnamon and remaining 2 tablespoons sugar in a small bowl. Shape dough into 20 (1 3/4-inch) balls; roll in cinnamon-sugar. Space 3 inches apart on parchment-lined baking sheets.
Bake until edges turn golden, 12 to 15 minutes. Let cool on sheets on wire racks.
After rolling balls of dough in cinnamon sugar, give them ample room on baking sheets; they spread quite a bit.