Rhubarb Crumble Bars: Sweet, Sharp & Perfectly Sliceable

Rhubarb crumble bars are a traybake version of the classic rhubarb crumble, combining a buttery base, tangy rhubarb filling, and a golden crumble topping. They’re easy to slice, simple to serve, and ideal for sharing.

This guide explains what rhubarb crumble bars are, how to make them, and tips for getting clean slices — ⭐ Recommended Products — 🌱 Rhubarb & Growing Essentials

Rhubarb is a hardy, productive perennial that’s great for desserts, compotes, and early spring harvests. These essentials will help you grow it successfully and enjoy its harvest year after year.

• Rhubarb Crowns / Plants
Established rhubarb crowns are the easiest way to start — strong plants ready to go in the ground or large containers. Look for reliable varieties like Victoria or Crimson King.
👉 Click here to see top options

• Rhubarb Forcers
Special covers used in early spring to ‘force’ tender, pale stems sooner than usual — perfect if you want early harvests and sweeter stalks.
👉 Click here to see top options

• Rhubarb Seeds & Starter Kits
If you prefer growing from seed, seed packs with quality varieties give you a head start — ideal for sowing under cover before transplanting later.
👉 Click here to see top options

• Garden Compost / Soil Improver for Rhubarb
Rich, well-drained compost or well-rotted manure helps rhubarb establish strong roots and produce big, healthy stems year after year.
👉 Click here to see top options

• Rhubarb Growing Guide & Plant Care Book
A helpful reference on planting, forcing, feeding, and harvesting — great for beginners or anyone wanting bigger yields.
👉 Click here to see top options

🍰 What Are Rhubarb Crumble Bars?

Rhubarb crumble bars are baked in a square or rectangular tin and cut into bars once cooled. They have three layers:

1. A shortbread-style base
2. A soft, slightly jammy rhubarb filling
3. A crunchy crumble topping

They’re popular for bake sales, lunchboxes, and afternoon tea.

🧈 Ingredients for Rhubarb Crumble Bars

Base & Crumble

• Plain flour
• Unsalted butter, cold and cubed
• Caster sugar
• Light brown sugar
• Pinch of salt

Rhubarb Filling

• Fresh rhubarb, chopped
• Caster sugar
• Cornflour
• Vanilla extract (optional)

🥣 How to Make Rhubarb Crumble Bars

1️⃣ Prepare the Tin

• Line a square or rectangular baking tin with parchment
• Leave some overhang for easy lifting

2️⃣ Make the Crumble Mixture

• Rub butter into flour until breadcrumb-like
• Stir in sugars and salt
• Reserve about one-third for the topping

3️⃣ Make the Base

• Press the remaining crumble mixture firmly into the base of the tin
• Bake at 180°C (160°C fan) for 15 minutes until lightly golden

4️⃣ Prepare the Rhubarb Filling

• Toss chopped rhubarb with sugar, cornflour, and vanilla
• Spread evenly over the warm base

5️⃣ Add the Crumble Topping

• Sprinkle the reserved crumble evenly over the rhubarb
• Don’t press it down — it should stay loose

6️⃣ Bake

• Return to the oven and bake for 35–40 minutes
• The topping should be golden and the rhubarb bubbling underneath

7️⃣ Cool and Slice

• Allow to cool completely in the tin
• Lift out using the parchment
• Slice into bars with a sharp knife

Cooling fully is essential for neat slices.

🍮 Serving Suggestions

Rhubarb crumble bars are delicious:

• Served cold as a cake bar
• Slightly warm with custard
• With whipped cream or ice cream
• As part of an afternoon tea spread

🔥 Tips for Perfect Rhubarb Crumble Bars

• Cut rhubarb into even pieces
• Don’t skip the cornflour — it thickens the juices
• Press the base firmly for stability
• Cool completely before slicing
• Store in the fridge for extra firmness

🌿 Easy Variations

• Rhubarb and ginger bars – add ground or stem ginger
• Rhubarb and strawberry bars – replace half the rhubarb
• Oaty crumble bars – add rolled oats to the topping
• Almond crumble bars – add flaked almonds

🌿 Final Thoughts

Rhubarb crumble bars capture everything people love about rhubarb crumble in a convenient, sliceable form. Sharp, sweet, and satisfyingly buttery, they’re easy to make and even easier to enjoy.

A brilliant bake for any rhubarb season.