Preheat the oven to 425° F. Rub a 10-inch cast iron skillet with butter.
In a bowl, combine the flour, cornmeal, baking powder, garlic powder, and salt. Using your hands, mix in 1 stick of shredded butter and the parmesan cheese. Pour over the milk and add the honey. Mix until just combined.
Turn the dough out onto a floured surface. Pat into a 1-inch-thick rectangle. Fold one side into the center, then the other side on top. Like a letter. Turn the dough horizontally. Flatten into a rectangle again. Repeat the folding. Turn the dough horizontally one more time. Flatten into a ¾-inch-thick rectangle.
Using a biscuit cutter, cut the dough into 3-inch circles. Re-roll the remaining dough and cut more circles. Arrange the biscuits in the prepared skillet. Brush the tops with milk. Arrange 2 tablespoons of butter around the biscuits. Bake until golden brown, 20-22 minutes.
Meanwhile, melt 2 tablespoons of butter in a small saucepan set over low heat, cooking until lightly browned, about 5 minutes. Remove from the heat and mix in the honey, thyme, and sea salt. Top with fresh thyme if desired.
Serve the biscuits warm with browned honey butter and flaky salt.
