Step 1

Spray the inside of a 6-quart crock pot with cooking spray.

Step 2

Layer the blueberries on the bottom of the crock pot.

Step 3

Stir in sugar, lemon zest and lemon juice; set aside.

Step 4

In a mixing bowl, combine oats, light brown sugar, flour, cinnamon, nutmeg and salt.

Step 5

Add the butter and cut it in with two knives or a pastry blender; cut and blend until mixture is crumbly.

Step 6

Sprinkle the oat mixture over the blueberries.

Step 7

Cover and cook on HIGH for 1 hour and 30 minutes, on LOW for 2 hours and 30 minutes.

Step 8

Remove cover and continue to cook for 30 more minutes.

Step 9

Serve.