In a medium-sized bowl, whisk together the maple syrup, liquid smoke, salt, and pepper, then add the mushrooms and toss gently to coat. Allow to marinate for 15 minutes.
In a large cast iron skillet over medium-high heat, melt the coconut oil.
Scoop out the mushrooms from the bowl and add to the skillet in a single layer and fry, turning occasionally, until the edges are dark and crisp, and smaller pieces are thoroughly crisped, around 10 minutes.
Remove from pan to a parchment-lined plate, then add to recipes as needed.