Slow-cooker apple cinnamon French toast

Name: Slow-cooker apple cinnamon French toast
Prep time: 20 min
Cook time: 3 h
Total time: 3 h 20 min
Cuisine: French
Ingredients: 300g brioche, cut into 2cm pieces; 2 granny smith apples, cored, chopped; 235g (1 cup) walnuts, coarsely chopped; 5.00 gm ground cinnamon; 80g (1/2 cup, lightly packed) brown sugar; 8 eggs; 500ml (2 cups) milk; 4.40 gm vanilla extract; Icing sugar, to dust; Double cream, to serve; Maple syrup, to drizzle