Preheat the oven to 350 degrees. Line a muffin tin with cupcake liners.
In a bowl, whisk together all of the wet ingredients.
In another bowl, whisk together all of the dry ingredients. Add the wet ingredients into the dry and gently stir to combine.
Using a 1/3 cup measure, ladle the batter into the liners. Bake for 18-22 minutes or until a toothpick inserted into the center comes out clean. Remove the muffins from the oven and let them cool on a baking rack.
Once the muffins are cooled completely, drain and rinse the soaked cashews. Add them to a high speed blender along with the coconut butter (see notes for melting methods), maple syrup, and lemon juice. Blend until completely smooth, scraping down the sides and using a tamper as needed. Frost the muffins and serve.