Preheat oven to 350°. Line an 8-inch square baking pan with parchment paper, letting excess extend over sides of pan; lightly spray parchment with baking spray with flour.
In a medium bowl, whisk together flour, oats, melted butter, sugars, and salt until crumbly. Press half of mixture into bottom of prepared pan. Arrange strawberries on prepared crust; dollop Quick Strawberry Jam all over berries. Sprinkle remaining flour mixture onto jam.
Bake until topping is golden brown and filling is bubbly, 55 minutes to 1 hour. Let cool completely in pan on a wire rack.
Refrigerate until cooled and firm, about 1 hour. Using excess parchment as handles, remove from pan, and cut into 2-inch squares. Refrigerate in an airtight container for up to 3 days.
Recipe by Bake from Scratch at https://bakefromscratch.com/strawberry-jam-crumble-bars/