Preheat oven to 350°F (175°C) and line a 6-cup muffin pan with cupcake liners.
Place coconut flour, cacao powder, tapioca starch, baking soda, and sea salt in a food processor and pulse until combined.
Add eggs, coconut milk, coconut oil, maple syrup, and vanilla extract to the dry ingredients; pulse until the batter is smooth and well-incorporated.
Divide the batter evenly among the 6 liners, filling each approximately 2/3 full.
Bake for 20 minutes until the centers are firm to the touch.
Remove cupcakes from the pan and transfer to a wire rack to cool completely.
In a high-powered blender, combine the soaked cashews, maple syrup, coconut oil, vanilla, and lemon juice.
Process on high speed until the frosting reaches a smooth, creamy consistency.
Chill the frosting in the refrigerator for 15 minutes to allow it to set.
Pipe or spread the frosting onto the cooled cupcakes and serve immediately or store refrigerated.