Preheat the oven to 350°F. Line a muffin pan with 14 liners.
In a medium mixing bowl, stir together the hazelnut meal, baking powder, salt, cocoa powder, and espresso powder, if using. Set aside.
In a large mixing bowl, stir together the melted coconut oil, honey, applesauce, eggs, and vanilla until well combined.
Add the dry mixture to the wet and stir just until combined. Divide the batter among the prepared liners. They should be about 4/5 full.
Bake for 17-20 minutes or until a toothpick inserted in the middle no longer comes out with raw batter on it. It should have some moist crumbs on it. If the toothpick comes out totally clean, the cupcakes are likely over-baked.
Let the cupcakes cool for 5 minutes in the pan and then remove to a wire rack to cool completely.
While the cupcakes are cooling, prepare the frosting. In a medium saucepan over low heat, mix together the coconut oil, hazelnut butter and cocoa powder. Stir until well combined and keep stirring until the mixture is melted.
Remove from the heat and add in the honey. The frosting will be very runny at this point but will firm up as it cools.
Let it cool for about 15 minutes or until no longer warm and then place the pan in the refrigerator for about 45 minutes or until the frosting is a nice spreadable consistency.
Spread about 4 teaspoons on top of each cupcake. Top with chopped hazelnuts, if desired.
Store in an airtight container at room temperature for 24 hours and refrigerate anything after that for up to 3 days.