Serves 8 to 10
1 cup finely ground gingersnap cookie crumbs from about 25 gingersnaps (4 ounces)
Zest of 1 lemon
4 Tablespoons unsalted butter
2 pints vanilla frozen yogurt
1 pint blueberry frozen yogurt
1. Line a loaf pan with parchment or wax paper, leaving an overhang on two sides.
2. Melt the butter and combine with the cookie crumbs, and zest in a small bowl. Set aside.
3. Remove one of the pints of vanilla frozen yogurt from the freezer and let sit until slightly softened, about 5 minutes. Dollop in the bottom of the pan, then smooth with a spatula. Top with a third of the cookie mixture, sprinkling evenly.
4. Chill in the freezer until firm, 30 minutes.
5. Remove the blueberry frozen yogurt from the freezer and repeat as above. Chill until firm, 30 minutes, then repeat with the remaining vanilla frozen yogurt.
6. Cover and freeze at least 4 hours and up to overnight.
7. Just before serving, dip the pan into hot water to loosen the frozen yogurt. Remove from the pan and invert onto a serving tray with the crumb layer on the bottom. Serve sliced.