In a large bowl, combine peanut butter and melted coconut butter. Stir with a spatula until the coconut butter is completely and evenly incorporated into the peanut butter.
Stir in the maple syrup. When you mix in the syrup, it should thicken the mixture. If needed you can add another 1/2 to 1 tbsp maple syrup if you desire a sweeter fudge.
Add fudge into prepared loaf pan. Smooth and even surface with a spatula. Place into freezer to set (about 30-60 minutes). When fudge is completely solid, remove from freezer. Let it soften for a few minutes at room temperature before cutting with a large sharp knife. The fudge becomes quite soft if left out at room temperature for a long time so store uneaten fudge pieces in a sealed container in the fridge or freezer.
Notes
Make sure to use natural peanut butter, which is peanut butter that has no added oils. Only peanuts and salt should be on the ingredient list. You can also substitute with natural almond butter.
This recipe works best with pure maple syrup. I don't recommend using honey or any sweetener with a thick consistency like honey because the fudge will not set as well. You can use a sugar-free sweetener that has a thin, maple syrup consistency.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.