I found this recipe in a Fix it and Forget it cookbook from the library. If you Google this recipe there are several with just a few variations.
Fudgy Chocolate Cake, 4 qt crock pot
1 cup flour
2 tsp baking powder
2 Tbsp butter
1/3 cup chocolate chips
1 cup brown sugar, divided
3 Tbsp, plus 1/3 cup Dutch Processed Cocoa, Divided
1 Tbsp vanilla
1/2 tsp salt
1/3 cup milk
1 egg yolk
1 1/2 cup hot water
1. Coat the inside of the slow cooker with cooking spray.
2. In a mixing bowl, whisk together the flour and baking powder, set aside.
3. In a large microwave safe bowl, melt the butter and chocolate chips in the microwave. Mix well.
4. Whisk in 2/3 cup of brown sugar, 3 Tbsp cocoa powder, vanilla, salt, milk and egg yolk.
5. Add the flour mixture and stir until mixed.
6. Pour batter into slow cooker and spread evenly.
7. Whisk together remaining 1/3 brown sugar, 1/3 cup cocoa powder and 1 1/2 cups hot water until the sugar is dissolved. Pour over batter in crock pot and NO NOT stir.
8. Cover and cook on High for 1/2 hours. You will know the cake is set when the edges begin to pull away from the sides of the pot.
9. Turn off crock pot and remove lid- try to not get the condensed steam from the lid onto the cake.
10. Let cool for 30 minutes. Spoon into bowls- make sure to get all the way to the bottom to get the gooey fudge.