Spray a 6-7 quart slow cooker with nonstick cooking spray or line with a slow cooker liner and spray that with cooking spray. (I used the liner, it’s not necessary except it makes for easy clean up.)
Stir cake mix, creamer, oil, and eggs in a large bowl with a whisk or a hand mixer until smooth. Pour into prepared slow cooker.
Heat water until boiling in a microwave or small sauce pan. Whisk in brown sugar and butter until the butter is melted. Slowly drizzle over the cake batter in the pan.
Cover the crock pot with a paper towel then place the lid on top. The paper towel is to catch any condensation so it doesn’t get the cake wet.
Cook on high power for 1 1/2 to 2 1/2 hours. There is quite a range of cooking time because all crock pots cook differently. Start peeking at the cake after 1 1/2 hours. Once it no longer looks like batter, check with a toothpick to check for doneness. A few crumbs will stick to the toothpick when it’s done.
Serve warm with caramel sauce and ice cream. Store in refrigerator for up to 3 days.