Strawberry Rhubarb Slab Pie Recipe — Perfect for Parties

In this strawberry rhubarb slab pie, the classic pairing of strawberries and rhubarb gets a bright lift from lime zest and fresh lime juice. The filling becomes jammy and sweet with a lively citrus note. The pie is finished with interwoven lattice strips, brushed with egg wash and sprinkled with coarse Turbinado sugar for a crunchy, golden top.

The aroma while this pie bakes is unmistakable—warm strawberries and buttery crust that announce summer. I had wanted to make a slab pie for a while; I’d saved several on my pie board because I love the idea of a large rectangular pie that showcases the crust.

Slab pies feel a bit like the sweet cousins of the sheet-pan pastries you find in bakeries. They put the crust in the spotlight because the filling-to-crust ratio is lower than a deep-dish pie. That means the crust needs to be excellent and the filling flavorful enough to hold its own.

For this pie I used the all-butter crust and technique from Sister Pie. The dough rolls smoothly, handles being cut into lattice strips and braids, and bakes into flaky, tender layers. It’s the kind of crust that stands out whether you keep the top simple or decorate it elaborately.

I wanted a lattice top so the bright filling could show through. The strawberries and rhubarb are too pretty to hide under a solid lid, and the juicy filling bubbling around the lattice creates a lovely sticky-sweet coating on the crust.

The lattice I made is a mix of thick strips, three-strand braids, and thin accents, all framed by a crimped outer edge. It’s a spontaneous, decorative layout; you can simplify it by using only wide strips or make it more intricate by adding more braids and thin pieces. The decorative elements are just accents—choose the pattern that suits you.

For a step-by-step tutorial on lattice techniques, refer to my detailed blog post on making lattice pie crusts for visual guidance.

Why make a slab pie?

Slab pies are perfect for feeding a crowd—one baking effort yields many servings. This recipe is designed for a quarter sheet pan (9 x 13 inches). Depending on slice size, you can get 12 to 15 pieces. It’s easy to serve, and the pieces are sturdy enough to enjoy by hand.

Recipe notes

• Quarter sheet pan – A quarter sheet pan measures 9 x 13 inches and has low rims. It’s different from a deep 9 x 13 baking pan; using a proper quarter sheet pan is recommended for even results.
• Pie dough – The recipe below doubles a standard pie dough so you have enough for a generous bottom crust plus ample lattice strips, braids, and decorative pieces. Extra dough gives you flexibility and reduces stress while assembling.
• Egg wash – Optional but recommended for a glossy, golden finish. If the top browns too quickly, tent the pie with foil during baking to prevent over-browning.
• Turbinado sugar – This coarse, golden sugar adds crunch and texture. If you don’t have turbinado, a light sprinkle of granulated sugar will work, though it won’t provide the same coarse crunch.

📖 Recipe

Strawberry Rhubarb Slab Pie

A flavor-packed pie made with floral strawberries, bright rhubarb, and fresh lime zest. Slab pies give you a larger crust-to-filling ratio, which pairs perfectly with this flaky all-butter dough.

AuthorKathleen Culver

Cook time1 hour 15 minutes

Servings12 slices

INGREDIENTS

Sister Pie’s All Butter Pie Dough

• 5 cups (600g) all-purpose flour
• 2 tsp (8g) granulated sugar
• 2 tsp (12g) kosher salt
• 2 cups (552g, 16 oz) unsalted butter, chilled
• 2 Tbsp (30mL) vinegar, apple cider or white vinegar
• 1 cup (250mL) cold water, (minus 2 Tbsp)

Strawberry Rhubarb Pie Filling

• 2 ½ cups (14 oz, approx. 400g) strawberries, hulled and quartered
• 3 ¾ cups (16 oz, approx. 450g) rhubarb, fresh, diced
• 1 cup (200g) granulated sugar
• lime zest, from one large lime
• 2 tablespoons lime juice, approximately ½ large lime
• ⅓ cup (40g) tapioca flour

Egg Wash (optional)

• 1 large egg
• 2 tablespoons heavy whipping cream
• ¼ to ½ cup turbinado sugar, to sprinkle over crust

INSTRUCTIONS

Making the dough

• Pour 2 tablespoons vinegar into a 1-cup measuring cup, then fill the rest with cold water. Place in the freezer briefly so the water chills but remains liquid.
• Whisk flour, sugar, and salt together in a large bowl.
• Cut chilled butter into 16 pieces and toss with the flour. Using a pastry blender, cut until the butter pieces are pea-sized.
• Add the chilled water-vinegar and use a bench scraper or spatula to work the dough until it forms a rough ball with no dry bits. Turn onto a floured surface, divide in two, shape each into a rectangle, wrap tightly, and refrigerate several hours or overnight.

Rolling out the bottom crust and lattice

• On a floured surface, place one dough rectangle and with the rolling pin held at one end, give it a few firm whacks while moving left to right. Rotate and repeat.
• Roll from the center outward until the dough is roughly 11 x 15 inches so it will overhang the 9 x 13 sheet pan by a few inches.
• Fold the dough into quarters and transfer to the sheet pan. Unfold and press into the base and corners. Chill the pan on a half sheet to support the overhang, covered with plastic wrap.
• Roll the second piece of dough similarly, folding into thirds and rolling again to create an even, flat rectangle. Cut lattice strips about ¾ inch wide on the diagonal. If you want braids or thin strips, divide a thick strip into three and braid or use the narrower pieces as accents. Chill the strips on a parchment-lined sheet.

Mixing the pie filling

• In a large bowl, combine strawberries, rhubarb, lime zest, lime juice, sugar, and tapioca starch. Gently fold until evenly combined. Spread the filling in the prepared crust.

Assembling the lattice

• Lay half the lattice strips diagonally across the filled pan with about an inch overhang. Fold every other strip back and lay a perpendicular strip across, then unfold to finish the weave. Continue until the lattice is complete.
• Trim the lattice edges to the pan edge, then roll the overhanging bottom crust inward over the lattice ends. Crimp the edge by pinching or using your preferred method. Chill the assembled pie for at least 30 minutes.

Baking the pie

• Preheat oven to 400°F (200°C) and place a rack in the lower third.
• If using egg wash, beat the egg with cream and brush over exposed crust. Sprinkle generously with turbinado sugar.
• Place the pie on a rimmed sheet lined with foil to catch spills. Bake in the lower third for 30 minutes, then tent with foil and bake another 30 minutes. Continue baking until the center juices are actively bubbling—this may take an additional 15 minutes (total about 1 hour 15 minutes). Let the pie cool until just warm so the filling can set before slicing.
• Slice and serve.