In a small bowl, combine flour, brown sugar, baking soda, baking powder and salt. Mix well.
1 ½ cup flour, ½ cup brown sugar, 1 tsp baking soda, 1 tsp baking powder, 1 dash salt, ¾ cup sugar
In a separate, larger mixing bowl, combine peanut butter, sour cream, butter and water. Mix well. Add dry ingredients to peanut butter mixture. Fold in chocolate chips.
1 cup chunky peanut butter, ¾ cup sour cream, 3 tbsp butter, 2 tbsp water, 1 cup chocolate chips
Generously grease a 6 quart slow cooker with nonstick cooking spray and spread/press batter into the crock.
In a measuring cup, heat half and half for 60 seconds at 50% power. Repeat for a second heating. Add sugar and cocoa powder to the half and half and whisk well. Pour on top of batter.
¾ cup half and half, ⅓ cup cocoa powder
Place the lid on the slow cooker and heat on high for 1-1/2 to 2 hours or until the edges begin to pull away from the side of the crock. The center will be jiggly and remain soft. Scoop onto a plate and serve with vanilla ice cream if desired.