Preheat oven to 180.

Peel sweet potatoes and microwave the chunks until soft.

Add the chunks to a food processor along with the pitted dates.

Stir all remaining ingredients apart from the buttons together in a large bowl. Add in the potato/date mixture and stir well.

Put into a lined baking dish. Cook for 45 minutes. If a fork does not come out clean it may need a few minutes more.

Pop your buttons on top after the brownie has been cooking for 10 minutes. It should be warm enough to still melt them slightly.

Cut when completely cool.