Recipe for Rhubarb and Custard Slice

This summer rhubarb is going to be the flavour on all our lips – whether in gin (as our editor likes it) or in desserts. We were very grateful when baking ingredients specialist Dr Oetker sent us this moreish recipe for a perfect summer dessert.

Rhubarb and Custard Slice

Combine these two classical taste combinations into this delicious sweet treat. Perfect for sharing.

Prep time 20 mins, plus chilling

Cooking time 1 hour

Serves 12


For the base

250g plain flour

1 ½tsp Dr Oetker Baking Powder

200g caster sugar

125g cold unsalted butter, cut into small cubes

1 egg

1tbsp of water

For the filling

90ml of water

50g caster sugar

800g rhubarb, cut into 6cm lengths

½tsp Dr. Oetker Madagascan Vanilla Natural Extract/Dr. Oetker Madagascan Vanilla Bean Paste

1 egg yolk

250ml double cream

75g caster sugar

3 medium eggs, 1 egg yolk

800g rhubarb, cut into 6cm lengths

250ml double cream

To serve

a dusting of icing sugar


  1. For the base; mix the flour, Baking Powder and 200g of the sugar, rub in the butter with your fingertips until it resembles fine breadcrumbs. Beat one of the eggs with 1tbsp of water then mix in using a butter knife. Then, without overworking, bring the mixture together with your hands to make a smooth dough. Cover and leave in the fridge for 30 mins.
  2. For the filling; in a wide pan bring 90ml of water mixed with 50g of sugar to the boil, reduce to a simmer then add the rhubarb in a single layer (you may need to do two batches), cover and cook for 3-4 mins until just tender. Remove with a slotted spoon and set aside on a plate to cool. In a jug mix the rest of the sugar, the eggs and yolk, cream and Vanilla Extract until just combined, set aside.
  3. Heat the oven to 180C, 160C fan, gas 4. Grease a 20cm x 30cm tray-bake or brownie tin. Take a sheet of baking parchment big enough to line the whole tin, trace the base of the tin in the middle then roll the dough out to cover it. Trim and reserve the excess pieces of dough. Snip from the tip of the parchment to the tip of the dough in each corner then set into the tin, tidy up the parchment and gently press the dough to the edges. Bake for 20 mins.
  4. Turn the oven down to 150C, 130C fan, gas 2. Carefully press strips of the reserved dough all along the edges of the tin the seal in the dough after any shrinkage from baking. Scatter the rhubarb, pour over the custard and bake for 40 mins or until the centre is set but with a slight wobble. Cool for at least 30 mins.

TIP – bubble down the leftover rhubarb juices until reduced by half. Use as a drizzling syrup on pancakes or freeze in ice-cube trays and add to drinks.

Prefer rice pudding? Then check out this recipe for a Cuban tasty take on this family favourite.