Crockpot Apple-berry crisp

Name: Crockpot Apple-berry crisp
Prep time: 30 min
Cook time: 2 h
Total time: 2 h 30 min
Cuisine: European, British
Ingredients: 3 apples; 1 pkg frozen berries; 4 Tbsp sugar; 2 Tbsp flour; 100g butter; 1 cup oats; 1/2 cup brown sugar; 1/2 cup flour; 1/2 tsp cinnamon; a sprinkle of nutmeg