Grapefruit Campari Bars

Step 1

To prepare the crust, preheat oven to 350°F. Pulse flour, powdered sugar, 2 tablespoons cornstarch, and 1/2 teaspoon salt in a food processor until combined. Top with butter pieces; pulse until mixture resembles coarse meal, 4 to 5 times. Drizzle evenly with oil; pulse just until moistened, about 2 times. (Mixture will be crumbly.) Transfer mixture to an 8-inch square glass baking dish coated with cooking spray. Pat into an even layer, being careful not to compact it. (Pressing too firmly will create a dense, tough crust.) Bake at 350°F until lightly browned all over, 25 to 30 minutes. Cool to room temperature.