Step 1

Preheat oven to 325 degrees. Butter a 10-by-15-inch rimmed baking sheet; line bottom with waxed paper. Butter paper; set aside. In a medium bowl, whisk together flour, baking powder, and salt; set aside.

Step 2

In a mixing bowl, cream butter and sugar until light and fluffy. Add eggs one at a time, beating well after each, then beat in vanilla. With mixer on low speed, add flour mixture, and mix until just combined (batter will be as thick as cookie dough).

Step 3

Spread batter evenly on prepared baking sheet; scatter cherries over the top. Bake cake until golden and a toothpick inserted in center comes out clean, 35 to 40 minutes. Cool 10 minutes in pan. Invert onto a wire rack; reinvert onto another rack to cool completely (top side up).

Step 4

To serve, cut cake into triangles with a serrated knife. Dust with confectioners' sugar, if desired.