I've made black bean brownies before in a slab tin and they were DF, GF, SF too. This recipe is adjusted slightly, tastes better and the nuts are a good addition.

Makes 18 small brownies about 2 tbsp each

400g can of black beans, drained

2 tbsp ground flaxseed stirred into 4 tbsp warm water and set aside for 5 min

1/4 c coconut oil

1/4 c cacao or cocoa powder

1/2 c rice malt syrup

1 tsp baking powder

1/2 tsp salt

1 tsp vanilla extract
chopped nuts for topping if desired

Preheat oven to 180C. I used little silicon moulds, which don't need greasing but you can use any tin shape - mini muffin tin, bundt etc
Just blitz all the ingredients except the nuts in a blender or food processor then spoon into moulds. Sprinkle nuts on top if using.
Bake for 25-30 min until cooked through. Leave to cool in the tins for 10 min before turning out onto a wire rack to cool completely.
These brownies are gooey, sweet and chocolatey - everything you want in a brownie - and the kids don't know they're getting added nutrition!