Preheat oven to 180°C (360°F). Place 200 g whole almonds and 200 g hazelnuts separately on a baking sheet. Roast in the oven for 15 minutes.
2: At the end of this time, remove as much skin as possible from the hazelnuts, see how to do it here. Note that unlike hazelnuts, almonds keep their skin, which is important for their taste.
4: Once the temperature has been reached, turn the heat down to medium and pour in the almonds and hazelnuts all at once.
5: Stir with a wooden spatula without interruption, the sugar will quickly "sand", and the dried fruit will become covered with white sugar. This is normal, so keep stirring.
6: Little by little, the sugar will caramelize...
7: ...and coat with almond and hazelnut caramel.
8: Pour the contents of the pan onto a sheet of baking paper placed on a baking sheet. Leave to cool.
9: Break the caramel slab into pieces and pour into a blender or food processor.
10: Start it up, it's noisy, you'll first get a powder...
11: ...Then a paste, it's the praline, stop the robot.
13: Pour them into the bowl of the food processor, add 1 tablespoon powdered cocoa, then blend for a few seconds.
14: Now your spread is ready, pour it into a jar and store in the fridge.
Remarks
You can vary the proportion of chocolate more or less according to your taste. If you only have almonds or hazelnuts, no problem either, your praline will just be more hazelnut- or almond-flavored, as the case may be.