Preheat oven to 350 degrees.
Place chopped strawberries in a separate small bowl. Stir in 1 Tbsp of sugar and the lemon juice; let sit for 5-10 minutes while you make crumble crust.
In medium bowl, combine dry ingredients and half the chocolate chips. Add melted butter and vanilla; mix until crumbly. Measure 1 cup of the crumble mix and set aside. Press remaining crumble into 13" x 9"- inch ungreased baking pan.
Spread strawberry preserves mixture over the top. Sprinkle on remaining chocolate chips.
Bake 30-35 minutes or until crumble topping is lightly browned.