Using a sieve over a bowl, sift together flour, baking powder, and salt; set aside. Cream butter in a large bowl, using a hand mixer on high speed, until fluffy, about 2 minutes. Add sugar and egg yolks; mix until sugar is dissolved and mixture is light, about 4 minutes. With mixer on low speed, slowly add flour mixture; mix until dough just begins to come together, about 1 minute.
Turn dough onto a lightly floured surface; bring it together with your hands. Divide dough in half and form 2 balls. Wrap each ball in plastic wrap; freeze for at least 30 minutes or up to 3 hours.
Arrange an oven rack in center of oven; heat to 350°. Grease a 10" springform pan with butter. Remove a ball of dough from freezer, unwrap, and grate, using the large holes of a box grater, directly into prepared pan. Gently pat grated dough to even it out. Spread jam evenly over dough, leaving about a 1⁄2" border around edges. Grate remaining dough over jam layer; pat gently until surface is even. Bake until light golden brown, about 25–30 minutes. Let cool completely in pan, on a rack, before cutting into wedges