Prep

• Preheat oven to 350°F (175°C).

• Grease or line a 9×13-inch (23×33 cm) pan with parchment, leaving overhang for easy lifting.

Prep the rhubarb

• Wash, trim, and chop 4 cups rhubarb into ½-inch pieces.

• If very tart, toss with 2–3 Tbsp of the sugar from your measured amount and set aside.

Mix dry ingredients

• In a large bowl, whisk together: 1½ cups all-purpose flour, 1½ cups granulated sugar, 1 tsp baking powder, ¼ tsp salt.

Mix wet ingredients

• In a separate bowl, whisk 3 large eggs, 1 cup milk, and 1 tsp vanilla extract until smooth.

• Slowly whisk in ½ cup melted butter (cooled slightly) until combined.

Make the custardy batter

• Pour the wet mixture into the dry mixture and whisk just until no dry streaks remain (don’t overmix).

• Fold in the chopped rhubarb gently so it’s evenly distributed.

Pan & level

• Pour batter into the prepared pan and spread evenly to corners. Tap the pan lightly on the counter to release air bubbles.

Bake

• Bake at 350°F (175°C) for 35–45 minutes, until the top is golden and the center is just set.

• A tester inserted near the center should come out with a few moist crumbs (not wet batter). The edges will look lightly browned.

Cool & set

• Cool in the pan on a rack for at least 45–60 minutes; the pudding-like center firms as it cools.

• For clean cuts, chill 1–2 hours.

Slice & serve

• Use the parchment overhang to lift out. Cut into bars with a sharp knife, wiping the blade between cuts.

• Optional: dust with powdered sugar or serve with a small dollop of whipped cream.

Store

• Refrigerate in an airtight container up to 4 days.

• To freeze, wrap bars individually and freeze up to 3 months; thaw overnight in the fridge.

Pro tips:

• If using very juicy rhubarb, toss it with 1 Tbsp flour before folding in.

• For extra “pudding” richness, swap half the milk for half-and-half.