Cream the softened butter on medium speed until light and fluffy, about two minutes. Add the sugar and egg yolks and beat until completely incorporated.
Mix together the flour, baking powder, and salt. With the mixer on low, add the dry ingredients to the butter until just incorporated.
Divide the dough in half and shape each into a narrow log. Wrap each log in plastic wrap and freeze for at least 30 minutes (and hour is better). Remove from freezer.
Preheat oven to 350°. Butter one of the following: an 8" springform pan, or a 7x7" square cake ring. If using a cake ring, line a small baking sheet with parchment paper and place the ring on top.
Grate the dough on the large holes of a box grater into a bowl. Alternately (and much faster), grate the dough in your food processor, using the grating disk. If you break the logs in half or thirds, they can fit into the shoot on their sides for fast grating.
Transfer the dough to a large mixing bowl. Add the chips into the dough grates and gently toss. Pour into the prepared pan or ring, and distribute evenly, pressing lightly to the edges.
Bake for 20-25 minutes, or until the top is lightly golden. Remove and cool in the pan, on a wire rack.