If you love rhubarb pie, this rhubarb slab pie is a must — it feeds a crowd (or one very greedy person!). A tender, flaky crust paired with sweet-tart rhubarb filling makes this the ultimate taste of spring.
Spring brings fresh rhubarb into markets and grocery stores, and for me that means pie season. Rhubarb’s firm stalks soften in the oven and release a luxuriously syrupy filling that balances sweet and tart beautifully. This slab pie is designed to be simple: minimal fuss, maximum reward.
What is a slab pie?
A slab pie takes the idea of a traditional round pie and scales it up in a sheet pan or a rectangular baking dish. The shape makes it faster to assemble and easier to slice, so you get more pie with less effort. Using pre-made pastry makes this particular recipe especially quick, though you can always use your favorite homemade crust.
What is rhubarb?
Although commonly treated like a fruit in desserts, rhubarb is actually a vegetable. It grows as a perennial with thick stalks and large leaves. Only the stalks are eaten; the leaves are mildly toxic and should be discarded. Rhubarb comes in red, green, or speckled varieties. While red stalks look more appealing, colour isn’t a reliable indicator of sweetness. The prime season runs from spring into early summer, and a technique called forcing can produce tender, pinker stalks earlier in the year.
Rhubarb in baking
Rhubarb is one of the easiest and most versatile baking ingredients: chop it, toss with sugar, and fold it into pies, crumbles, cakes or tarts. Its natural tartness pairs particularly well with sweeter fruits like strawberries, but it also stands on its own when you want a clean, bright rhubarb flavour. In this slab pie the rhubarb gets to shine without too many additions.
Making the pie
This pie comes together fast — about 20 minutes of hands-on prep, plus baking time. Use two sheets of pre-rolled pastry, one slightly larger for the base. Toss chopped rhubarb with sugar, a little flour and lemon zest, fill the lined pan, cover with the second sheet of pastry, crimp the edges, brush with beaten egg and sprinkle a little raw sugar on top for sparkle. Bake until the crust is golden and the filling bubbles through the vents.
Recipe tips and notes
- Choose firm, crisp stalks. Avoid woody or wilted pieces. Colour is not the best indicator of sweetness — focus on texture and freshness.
- No need to precook the rhubarb. Dice it into small pieces so it softens fully while the pie bakes.
- Let the pie cool for at least an hour before slicing. Cooling helps the filling set so slices hold together.
- Serve warm or at room temperature with ice cream or whipped cream for a creamy contrast to the tart filling.
Storage and leftovers
Store leftover pie covered at room temperature for up to two days, or refrigerate for up to four days. To freeze, cool completely, then wrap well and freeze for up to two months. Reheat slices at 180°C / 350°F for about ten minutes if you prefer them warm.
More rhubarb ideas
- Rhubarb curd
- Rhubarb custard crepe cake
- Rhubarb Moscow mule
- Rhubarb crumble
- Rhubarb cobbler
Rhubarb Slab Pie
By Julia Frey of Vikalinka
Prep: 15 mins • Cook: 45 mins • Total: 1 hr • Servings: 8
A classic rhubarb pie made easier with sheet-pan pastry — crisp, golden crust and a bubbling tart-sweet filling.
Ingredients
- 700 g (about 25 oz) pre-made pie pastry (two rectangular sheets)
- 800 g (about 8 cups) fresh rhubarb, chopped
- 200 g (1 cup) sugar
- Zest of 1 lemon
- 1 tablespoon flour
- 1 egg, lightly beaten (for egg wash)
- 1 tablespoon Demerara or Turbinado sugar, for sprinkling
Instructions
- Preheat the oven to 400°F / 200°C.
- Chop the rhubarb into roughly 1/4-inch pieces. Toss with the sugar, flour and lemon zest in a bowl.
- Roll out the pastry to fit a 9″×13″ shallow pan or a similar sheet pan. Line the pan with the larger pastry sheet so the edges come up the sides.
- Fill the lined pan with the rhubarb mixture, then cover with the second sheet of pastry. Crimp the edges to seal. Optionally, use leftover pastry to cut shapes for decoration.
- Brush the top with the beaten egg, cut a few slits to vent, and sprinkle with the Demerara/Turbinado sugar.
- Place the pie in the oven, immediately reduce the temperature to 350°F / 180°C, and bake for 45 minutes or until the crust is golden and the filling is bubbling through the vents.
- Allow the pie to cool for about 1 hour before slicing so the filling firms up. Serve with whipped cream or ice cream if you like.
Nutrition (approx.)
Per serving: Calories 535 • Carbohydrates 74 g • Protein 7 g • Fat 24 g • Saturated fat 7 g • Sodium 370 mg • Fiber 4 g • Sugar 28 g