Preheat the oven to 160 °C top/bottom heat. Finely grind the nut variety and half of the roasted hazelnuts in the food processor or chop finely with a knife. Roughly chop the chocolate. Then mix the chopped nuts and chocolate with the flour, sugar, cocoa powder, gingerbread spice, baking powder, baking soda and salt. Now add the oil, plant-based milk and apple puree and mix everything quickly to form a smooth batter.
Prepare four heatproof glasses, each with a capacity of around 200 ml, by coating them thinly with the remaining oil. Fill the glasses halfway with batter, top with the remaining roasted hazelnuts and bake for 25 minutes. Then leave the brownies to cool completely.
Tip: You can also prepare the brownies the day before. They taste even better after being left to soak overnight!