Roasted Hazelnut soil?

Dry roast the nuts in a pan or skillet until golden, keep them moving at all times. Let them cool completely on a paper towel. Grind them to the right particle size you need. Spread them thinly and evenly on an oven tray and bake at somewhere around 140-160C. You will likely end up with some parts a little burnt. Or do whole nuts in a coffee roaster.

I've tried with pumpernickel bread and had good result.

I toasted the bread to give it a more black color (and flavor), and also added some finely chopped black olive and some crushed sunflower seeds.

You'd get the same result (different taste) by using roasted nuts.

I ended up putting about a 1/3 cup of unsalted whole roasted Hazelnuts in a food processor and ground them up fine. Then I toasted them in a small frying pan stirring constantly until golden. Then I put them in a 9x9 baking pan in the oven for about 15 minutes at 300 degrees.

The result:

Crush the nuts first (for more surface area) and then dry toast them on a barely oiled cookie sheet. {jelly roll pan, actually}

I use a toaster oven for small batches (stirring them once or twice), since a handful of roasted/toasted nuts is often all I need. WATCH them carefully while toasting; burning yummy ingredients is a major sad! :-(