Baked Mixed Berry Crumb Tarts with Oat Crust

Steps

1. Preheat the oven to 375°F (190°C) and set out two 9-inch tart pans with removable bottoms.
2. Make the oat dough: in a large bowl, stir together the flour, oats, brown sugar, salt and cinnamon, then stir in the melted butter until evenly moist and crumbly.
3. Set aside one quarter of the oat dough in a small bowl and stir the pecans into it; this is the crumble topping.
4. Divide the remaining three quarters of the oat dough evenly between the two pans, half in each, and press firmly over the bottoms and up the sides.
5. Bake the crusts for 12 minutes until just set and lightly golden at the edges; leave the oven on.
6. While the crusts bake, make the filling: in another bowl, whisk together the granulated sugar, cornstarch and lemon zest.
7. Add the frozen blueberries, strawberries, lemon juice and vanilla to the sugar mixture and toss until the berries are evenly coated.
8. Spoon half the berry filling into each warm crust, then scatter half the crumble topping over each tart, leaving the berries peeking through.
9. Set the pans on a baking sheet to catch drips and bake for 40 to 45 minutes, until the crumble is golden and the berry juices bubble thickly in the center.
10. Cool the tarts in their pans on a rack for at least 2 hours so the filling sets, then remove the rings and cut each tart into 6 slices.