Strawberry Rhubarb Crumb Pie

I make this pie every spring, and have ever since @joythebaker published the recipe almost ten years ago! It’s basically the marriage of a strawberry pie and a rhubarb crumble. True love. The pie crust is amazing, but I have also made it with a store bought crust. My favorite way to eat it is the day after with a hot cup of coffee 💫

Crust:
1 1/4 cups all-purpose flour
1 tablespoon sugar
1/2 teaspoon salt
1/2 cup cold unsalted butter, cut into small chunks
1/4 cup cold buttermilk
Filling:
3 cups sliced rhubarb, 1/2” thick (1 pound)
1 lb. strawberries, hulled and sliced in half
1/3 cup light brown sugar, packed
1/2 cup granulated sugar
1/4 cup cornstarch
large pinch of salt
2 tablespoons fresh lemon juice
Topping:
3/4 cup flour
3/4 cup old-fashioned oats
2/3 cup granulated sugar
large pinch of salt
6 tablespoons cold unsalted butter, cut into small chunks
1/2 cup unsweetened coconut flakes

In a bowl, whisk together flour, sugar, and salt. Add butter and work it into the flour mixture. Create a well in mixture and pour in buttermilk. Use a fork to combine. Add a bit more buttermilk if necessary.

On a lightly floured work surface, kneed dough into a disk and wrap in plastic wrap. Refridgerate for 1 hour.

On a well floured surface, roll the crust into about 12 inches in diameter. Transfer to a pie pan. Fold and crimp the crust with your fingers or a fork. Refrigerate for 30 minutes, and up to 3 hours.

For the Filling:
In a medium bowl, toss together rhubarb, strawberries, sugars, cornstarch, salt, and lemon juice.

Topping:
In a bowl, whisk together flour, oats, sugar, and salt. Add the cold butter chunks and using your fingers, work the butter into the flour mixture. Add the coconut and toss to combine.

To Assemble the Pie:
Place a rack in the center of the oven and preheat oven to 400 degrees.

Toss a handful (about 1/2 cup) of the topping mixture into the fruit mixture. Dump the fruit mixture into the pie crust. Top with topping mixture. Place on a baking sheet and place in the oven.

Bake for 20 minutes at 400 degrees, then reduce to 350 degrees and bake another 40 minutes. Cool 2 hours to thicken.