Spread the hazelnuts evenly on the pan and roast at 325°F for 15 minutes until they are golden and slightly oily on top. Watch carefully in the last minutes to prevent burning.
Remove the hazelnuts from the oven and let them cool on the pan for about 10 minutes until they are comfortable to handle.
Place the de-skinned hazelnuts into a high-speed food processor. Start on a low speed until the nuts break down into a coarse meal, then gradually increase the speed.