Peel the plantains by slicing the ends off, then cutting the plantains in half lengthwise. Use a sharp knife to carefully make a slit into the outer peel without cutting into the actual plantain. Peel the outer layer off, then slice the plantains into 1/4 to 1/2 inch chunks.
Heat the coconut oil in a large skillet over medium low. Add the plantains to the pan in a single layer (you may need to do this in a couple of batches, depending on the size of your skillet).
Cook the plantains for 2 to 3 minutes per side, or until golden brown and caramelized. Transfer to a cooling rack or plate lined with paper towels.
While they're hot, dust the cooked plantains with cinnamon sugar and a small pinch of sea salt. Serve warm, alone or with dairy-free ice cream!