Step 1Combine the flour, sugar, salt and lemon zest in a mixing bowl. Cut the butter into half-inch thick slices and add to the bowl. Using the tips of your fingers or a pastry blender, work the ingredients together until the mixture resembles coarse crumbs. Add a scant tablespoon or two of cold water and toss until the mixture just clings together. Gather into a ball. Wrap tightly in plastic film and chill 30 minutes.
Step 2Transfer the dough to a 9-inch springform pan. Press out evenly across the bottom and about 1 inch up the side. Prick the bottom of the crust all over with a fork. Freeze 30 minutes. Heat the oven to 375 degrees.
Step 3Bake the crust until it is set and lightly browned, 25 to 30 minutes. Cool completely.
Step 4Spread the mascarpone evenly over the cooled crust. Arrange the strawberries decoratively over the top in overlapping rows.
Step 5Combine the jelly and Cointreau in a small saucepan and heat, stirring, until the jelly dissolves. Lightly brush over the strawberries to glaze. Chill 1 hour before cutting.