Whenever I bake with rhubarb, my gal Friday Beckie reminds me that it’s poisonous. “Only the leaves, Beckie!” I insist in sing-song every time she turns her nose up at a crumble or piece of pie. Even the numerous internet articles I’ve shared with her praising rhubarb’s tart flavor and salubrious benefits couldn’t convince her otherwise (to be fair, no one should trust the internet).
But I’ve finally discovered the perfect vehicle to trick Beckie into enjoying this heretofore dubious fruit: raspberry rhubarb bars. Of course akin to the more traditional lemon bar (or our own mango bars, featured here), these treats pair a rich shortbread crust with a tangy and sweet custard that you’d want to eat even if it were poison.
Parbake the shortbread in a 8” by 11” pan before filling with the . . . well, filling. Pull it out when it’s set but still jiggling, and I promise you’ll have a hit on your hands to convince even the most hardened rhubarb rejector.
But don’t tell Beckie there’s rhubarb in these. It kind of slipped my mind.
- 1 cup butter, softened
- 1 cup sugar
- 2 cups flour
- ¼ tsp salt
- 2 cups raspberries
- 2 cups chopped rhubarb
- 1¼ cup sugar
- 3 tbsp flour
- 2 large eggs
- zest of one lemon
- 1 tbsp lemon juice
- Place a rack in upper third of oven and preheat to 350F. Grease an 8” by 11” pan or casserole dish and line with parchment.
- Make the crust—In the bowl of a stand mixer fitted with a paddle attachment, beat together butter and sugar until fully incorporated and fluffy, 3 to 5 minutes. Scrape down sides of bowl before adding flour and salt. Beat until just combined—do not over-mix.
- Turn out dough into prepared dish and use your hands or a spatula to spread evenly into the corners and sides. Parbake for 15-20 minutes until edges are just set and slightly browned.
- In the bowl of a food processor, combine 2 cups raspberries and 2 cups chopped rhubarb (using only the stems and discarding the leaves). Pulse until pureed.
- Strain raspberry/rhubarb mixture through a sieve to remove seeds, pressing down with a spatula to extract the most juice.
- Make the filling— While the crust bakes, in a large bowl, whisk together eggs and sugar until combined and glossy. Add raspberry/rhubarb puree, flour, lemon juice, and zest and whisk until combined.
- Pour filling over hot crust and return to oven. Bake for an additional 25-30 minutes, until filling is set but still slightly jiggly in the center.
- Cool completely before slicing. Dust with powdered sugar if desired. Store for up to a week in the refrigerator in an airtight container.