These rhubarb white chocolate blondies have the soft, chewy satisfaction of a brownie, with a deep butterscotch flavor, crunchy almonds, and pockets of tart rhubarb to break up the sweetness.
With rhubarb season in full swing, there’s never a shortage of rhubarb in my kitchen. I came across a recipe for rhubarb white chocolate blondies in The Joyful Home Cook cookbook by Rosie Birkett and decided to give it a try. The result was surprisingly delicious. I love how easily these blondies whipped up and they were soft and chewy with pockets of tart rhubarb to break up the sweetness.
- Sugar: for blondies you want that signature butterscotch flavor so brown sugar is the best. Muscovado, light brown sugar or dark brown sugar will work.
- Chocolate: when it comes to blondies, dark chocolate is the default but white chocolate complements the rhubarb. I chopped the chocolate into little pieces and left some larger chunks so you get pocket of white chocolate throughout the blondies.
- Nuts: nuts lend textural contrast to the soft, chewy blondies. Almonds and hazelnuts work great for this recipe.
- Rhubarb: to get the best tasting rhubarb, look for stalks that are dark red and thinner. They tend to be sweeter and more tender compared to the thicker stalks that are more fibrous.
How to Roast the Rhubarb
Roasting rhubarb with a generous amount of sugar will intensify its flavor and reduce the tartness. I roasted the rhubarb in a mixture of orange juice, zest, vanilla bean, and sugar. I only roasted the rhubarb for 12 minutes to soften and add sweetness to them. They'll be cooked further when you bake the blondies.
Tips for Making Blondies
- Melt the butter: By melting the butter before mixing it with the sugar, you can quickly add the rest of the ingredients and combine everything with just a whisk. There's no need to pull out your kitchen mixer.
- Use one bowl: mix the butter, sugar, egg, and vanilla before adding the dry ingredients and then the chopped chocolate and almonds.
- Do not over mix the batter: over mixing can stimulate gluten formation resulting in dense and dry blondies. Once you add the dry ingredients, whisk everything until they just come together.
- Line your pan with parchment paper: lining your pan means you can use the paper as a sling to easily pull the still-warm blondies out after they’re baked.
How long to bake the blondies
Bake the blondies until the edges are brown and the center is set, about 30-35 minutes. Cool the blondies briefly before using the sling to move them to a cutting board and cutting into 12 squares.
I could hardly wait for these rhubarb white chocolate blondies to cool down! They have the soft, chewy satisfaction of a brownie, with a deep butterscotch flavor, crunchy almonds, and pockets of tart rhubarb to break up the sweetness. These blondies were utterly delicious and left me convinced that rhubarb doesn't belong to just pies, tarts, and crumbles.
Rhubarb white chocolate blondies (adapted from the Joyful Home Cook cookbook)
- 1 cup rhubarb, cut into 1 inch pieces
- ¼ cup granulated sugar
- 1 vanilla bean, split lengthwise, seeds scraped
- zest and juice of 1 small orange
- ½ cup unsalted butter, melted
- ¾ cup brown sugar
- 1 large egg
- ½ teaspoon vanilla extract
- 1 cup all purpose flour
- ½ tsp baking powder
- ¼ teaspoon salt
- 3 oz white chocolate, chopped
- ½ cup sliced almonds
- ½ tablespoon powered sugar for serving
- Preheat the oven to 350 degrees F. Line a baking tray with parchment paper.
- Place the rhubarb on the tray in a single layer and scatter over the sugar. Scrape out the vanilla seeds over the rhubarb and throw on the pod along with the orange juice and zest Cover tightly with foil. Bake for 12 minutes, until the rhubarb is just soft. Set aside to cool. Drain the rhubarb from its syrup and set aside, reserving the syrup for another dish.
- Line a rectangular baking pan, approximately 10 x 8 inch.
- Melt the butter over medium heat until melted and light golden brown.
- In a large mixing bowl, whisk the browned butter and sugar until well combined and not lumpy.
- Add the egg and vanilla extract and stir until smooth.
- Place a sifter over the bowl, add flour, baking powder, and salt. Sift the dry mixture over the wet mixture. Whisk everything until just combined.
- Fold in the chopped white chocolate and sliced almonds, reserving 2 tablespoons of almonds.
- Pour the batter into the prepared pan and use an offset spatula to smooth into an even layer. Top with the roasted rhubarb. Scatter the rest of the almonds over the top.
- Bake until the edges are browned and pulling away from the pan, and a tester inserted in the center comes out clean, 30 to 35 minutes.
- Cool completely in the pan on a wire rack. Grab the excess parchment and lift the blondie slab out of the pan and onto a cutting board. Cut into 12 squares.
- Sprinkle with powdered sugar before serving. (optional)