Raspberry-Rhubarb Slab Pie

Total Time

Prep: 30 min. + chilling Bake: 45 min. + cooling

Makes

24 servings

Updated: Apr. 24, 2022
Slab pie is a pastry baked in a jelly-roll pan and cut into slabs like a bar cookie—or a pie bar, if you will. My grandfather was a professional baker and served pieces of slab pie to his customers back in the day. Here is my spin, featuring rhubarb and gorgeous red raspberries. —Jeanne Ambrose, Milwaukee, Wisconsin

Ingredients

  • 3-1/4 cups all-purpose flour
  • 1 teaspoon salt
  • 1 cup butter
  • 3/4 cup plus 1 to 2 tablespoons 2% milk
  • 1 large egg yolk, room temperature
  • 2 cups sugar
  • 1/3 cup cornstarch
  • 5 cups fresh or frozen unsweetened raspberries, thawed and drained
  • 3 cups sliced fresh or frozen rhubarb, thawed and drained
  • VANILLA ICING:
  • 1-1/4 cups confectioners' sugar
  • 1/2 teaspoon vanilla extract
  • 5 to 6 teaspoons 2% milk

Directions

  1. In a large bowl, combine flour and salt; cut in butter until crumbly. Whisk 3/4 cup milk and egg yolk; gradually add to flour mixture, tossing with a fork until dough forms a ball. Add additional milk, 1 tablespoon at a time, if necessary.
  2. Divide dough in 2 portions so that 1 is slightly larger than the other; cover each and refrigerate 1 hour or until easy to handle.
  3. Preheat oven to 375°. Roll out larger portion of dough between 2 large sheets of lightly floured waxed paper into an 18x13-in. rectangle. Transfer to an ungreased 15x10x1-in. baking pan. Press onto the bottom and up sides of pan; trim crust to edges of pan.
  4. In a large bowl, combine sugar and cornstarch. Add raspberries and rhubarb; toss to coat. Spoon into crust.
  5. Roll out remaining dough; place over filling. Fold bottom crust over edge of top crust; seal with a fork. Prick top with a fork.
  6. Bake until golden brown, 45-55 minutes. Cool completely on a wire rack.
  7. For icing, combine confectioners' sugar, vanilla and enough milk to achieve a drizzling consistency; drizzle over pie. Cut pie into squares.

Test Kitchen Tips
  • This pie dough can be made ahead of time and frozen. Thaw overnight in the fridge.
  • Before refrigerating or freezing pie dough, shape it into two rectangles so it's easier to roll into larger rectangles later.
  • Rhubarb
    If using frozen rhubarb, measure rhubarb while still frozen, then thaw completely. Drain in a colander, but do not press liquid out.

    Nutrition Facts

    1 piece: 247 calories, 8g fat (5g saturated fat), 29mg cholesterol, 159mg sodium, 42g carbohydrate (25g sugars, 2g fiber), 3g protein.