Preheat oven to 350°F (175°C).

Spread hazelnuts on a baking sheet in a single layer and roast for 10 minutes or until skins are dark and cracked.

Transfer warm hazelnuts to a clean kitchen towel and rub vigorously to remove as much skin as possible.

Place the warm, skinned hazelnuts into a high-speed blender or food processor.

Process on high for 5 to 8 minutes, scraping down sides as needed, until the hazelnuts release their oils and form a completely smooth, liquid butter.

Add the cocoa powder, powdered sweetener, vanilla extract, and salt to the processor.

Process for another 1 to 2 minutes until the dry ingredients are fully integrated.

Slowly stream in the melted coconut oil while the processor is running to reach the desired creamy consistency.

Transfer the mixture to a glass jar and allow it to cool and thicken at room temperature.