Preheat oven to 425°F. Line a large sheet pan, or other baking tray, with parchment paper or foil and set aside.
Place self-rising flour into a large bowl. Add chilled coconut oil that has been separated into small pieces. Use your fingers, or a pastry cutter, to rub the coconut oil into the flour until it is the size of small peas, or smaller.
Add coconut milk to flour and coconut oil mixture. Using wooden spoon or silicone spatula, mix everything together until you have a fairly uniform, stiff dough. The flour might not look all mixed in and that's okay. It will come together.
Dump the shaggy dough out onto a lightly floured surface. Using your hands, or a bench scraper, gently bring everything together, folding the dough over itself until all the dry bits are incorporated. Do not knead the dough.
With a bench scraper or knife, cut into four smaller squares. Stack the pieces of biscuit dough on top of each other.
Press it all down into a square again. Repeat this cutting and stacking procedure 2 more times.
Roll or pat the dough to about ½ inch thick. Use a 2 inch biscuit cutter or cookie cutter to cut out your biscuits.
Gather your scraps as you go and gently re-form them together and cut as many biscuits as you can.
Brush the tops of the biscuits lightly with more coconut milk. Sprinkle the top of each biscuit with flaky sea salt, if desired. Bake in a 425°F oven for 13 to 15 minutes, or until golden brown.