Strawberry-Rhubarb Crumble from Smitten Kitchen (adapted to lower-sugar and grain-free)

I've had freezer rhubarb burning a hole in my pocket for months. Once it became spring, aka "rhubarb season," I started making stuff with it again like Rhubarb Swamp Pie and Rhubarb Comstock. We also bought a pint of organic strawberries that we somehow kept forgetting to use, and instead of molding in the fridge, they became slightly dehydrated. I decided they were still okay, and this Smitten Kitchen crumble recipe had been made and posted by someone else recently, and I just had to make it too. But I subbed the sugar for coconut sugar and the flour for almond flour, and it was great, delicious. I will put her recipe below (please see her blog for detailed photo instructions and other general deliciousness) and indicate the changes I made.

The texture of the berries made them keep their shape a bit more, so file that thought away for the future! I can also say I have now used all the rhubarb. And I used my trusty oval dish that always seems to be more crumble/crisp/cobbler friendly even though it is smaller in volume to most recommended dishes. It just seems to work for me.

Strawberry-Rhubarb Crumble
(recipe from Smitten Kitchen, see notes below for how I made it lower-sugar and grain-free)

Yields 6 to 8 servings.

For the topping:
1 1/3 cup flour*
1 teaspoon baking powder
3 tablespoons sugar*
3 tablespoons Demerara sugar (or turbinado sugar aka Sugar in the Raw)*
Zest of one lemon
1/4 pound (1 stick or 4 ounces) unsalted butter, melted

For the filling:
1 1/2 cups rhubarb, chopped into 1-inch pieces*
1 quart strawberries plus a few extras, hulled, quartered
Juice of one lemon
1/2 cup sugar*
3 to 4 tablespoons cornstarch
Pinch of salt

1. Heat oven to 375°F. Prepare topping: In a mixing bowl, combine flour, baking powder, sugars and lemon zest and add the melted butter. Mix until small and large clumps form. Refrigerate until needed.

2. Prepare filling: Toss rhubarb, strawberries, lemon juice, sugar, cornstarch and a pinch of salt in a 9-inch deep-dish pie plate.

3. Remove topping from refrigerator and cover fruit thickly and evenly with topping. Place pie plate on a (foil-lined, if you really want to think ahead) baking sheet, and bake until crumble topping is golden brown in places and fruit is bubbling beneath, about 40 to 50 minutes. 

Notes from JennyBakes:

I used 1 1/3 cup almond flour and 1/3 cup tapioca flour for teh crumble - I often use tapioca with nut flours to increase the elasticity slightly. It isn't required. I subbed coconut sugar for the sugar and only used 3 tbsp in the crumble (did not include the 3 for Demerara/turbinado) and used almost 1/2 cup in the filling - I was running low so might have opted to match it more equally. I didn't have fresh lemons so skipped the zest in the topping and used bottled juice in the filling. Crumbles are pretty forgiveable so it all worked out fine!