Preheat the oven to 350 degrees, and line an 8-inch square pan with parchment paper. Lightly spray with cooking spray. Set aside. In a large bowl, beat together the butter and powdered sugar. Add in the salt and vanilla extract. Add in the flour and beat until a dough forms. Press about 2/3 of the dough into the bottom of your prepared pan, spreading evenly. Bake in your preheated oven for 10-12 minutes, or until just slightly golden on the edges.
With the remaining dough, mix in the oats. This should create a more crumbly dough. Set aside, uncovered (to create a more dry crumb).
In a medium saucepan over medium heat, stir together the strawberries, sugar, lemon juice, lemon zest, salt, cornstarch, and apricot jam. Cook the mixture, stirring frequently, for about 5-8 minutes, or until the mixture is thickened and jammy.
Spread the mixture over the cooked crust evenly- no need to cool either the filling or the crust. Break apart the crumb topping and press into small pieces and crumbs and evenly spread over the top, leaving the pockets of the jam layer still visible. Bake for another 25-30 minutes, or until the crumb topping is golden brown. Cool completely in the pan before removing and slicing. Enjoy!