Unless you've sworn to chocolate this Sweetest Day, give this one a try. It's not for the faint of heart. It takes a bit of work, but it's well worth it.
- Nonstick vegetable oil spray (I use canola)
- 1/2 cup (1 stick) unsalted butter, room temperature
- 1/4 cup creamy natural peanut butter (I use Smuckers all natural)
- 1/2 cup sugar
- Large pinch of salt
- 1 teaspoon vanilla extract
- 1 1/4 cups all purpose flour
- 1/3 cup blackberry jam
- Spray bottom of 9-inch-diameter springform pan with nonstick spray.
- Beat butter and peanut butter in large bowl until smooth, about 2 minutes.
- Add sugar and salt and beat until fluffy, about 2 minutes.
- Beat in vanilla.
- Add flour; beat on low speed just until blended.
- Transfer 1/3 cup dough to work surface. Shape into 1/2-inch-thick disk, place on plate, and freeze until hard, about 1 hour.
- Press remaining dough evenly over bottom of prepared pan.
- Spread jam over dough in pan, leaving 1/3-inch plain border. Refrigerate while dough disk freezes.
- Preheat oven to 350°F. Using large holes of box grater, grate frozen dough evenly over jam.
- Bake shortbread until dough edge is deep golden and grated dough on top looks dry and baked through, about 50 minutes.
- Cool shortbread completely in pan. Release pan sides. Cut into wedges.
Release pan sides. Cut shortbread into wedges.