Make the brownie base layer: soak the dates in boiling water and then drain them, saving some of the water. Add the dates to a blender with the oat flour, cacao powder and salt. Blend to a sticky dough, adding 1-2 tbsp of date water as needed.
Pour into a lined dish (about 6-inch square) and press down firmly.
For the cookie dough layer: clean out the blender and add in the chickpeas, cashew butter, maple syrup, oat flour, vanilla essence, pumpkin spices, and salt. Blend until really smooth and creamy. Pour into a bowl.
Chop the chocolate into small pieces and stir into the cookie dough. Pour over the brownie base and press down. Freeze for 30-60 minutes or until firm to touch.
Melt the chocolate for the topping layer.
Using a sharp, hot knife, carefully slice the brownie cookie dough into 9 squares or bars.
Dip each square into the chocolate, place on a lined tray and sprinkle flaky salt. Leave to set in the fridge for 10 minutes and enjoy.
Store the bars for 5-7 days in the fridge in an airtight container or freeze for up to 1 month.