In a large slow cooker, combine the strawberries, lemon juice, coconut sugar, and 2 Tbsp all-purpose flour.
Stir until well combined and spread the berry mixture into an even layer across the bottom of the slow cooker bowl.
In a separate bowl, mix the remaining all-purpose flour with the brown sugar and vegan butter. Use a pastry cutter (or use the tines of a large fork or a metal whisk) to crumble and combine the mixture until the mixture is sandy with some larger lumps.
Fold the rolled oats into the butter mixture, stirring until well combined.
Sprinkle the topping evenly over the strawberry mixture in the slow cooker and cover with the lid.
Cook on high for 40 minutes, then remove the lid and cook on high for another 40 minutes.
Serve your crisp warm or enjoy it chilled! Toppings like vegan yogurt, coconut milk, or vegan whipped cream are extra delicious here.