Step 1

Whisk the flour, brown sugar, sugar, cinnamon and salt together in a medium bowl.

Step 2

Cut in the cold butter with a pastry cutter or a fork until it forms a crumbly mixture that’s fully combined.

Step 3

Stir in the oats and set aside.

Step 4

Stir all the filling ingredients together in a slow cooker until fully combined then crumble on the topping.

Step 5

Cover the pot and cook on low for 3 ½ hours or on high for 2 hours.

Step 6

Remove the lid and let it stand for 1 hour or until the topping is fully hardened then serve with vanilla ice cream and a sprinkle of ground cinnamon if desired.