In a large bowl, mix together the cornmeal, flour, baking powder, salt, and sugar (if using).
In a separate bowl, whisk together the egg, buttermilk, and water.
Pour the wet ingredients into the dry ingredients and stir until just combined. The batter should be thick but pourable; add a little more buttermilk if needed.
Heat the bacon grease, lard, or vegetable oil in a large cast-iron skillet over medium heat.
Drop 2-3 tablespoons of batter into the skillet for each hoecake, spreading it slightly to form a small, round cake.
Cook until the edges are crispy and the bottom is golden brown, about 2-3 minutes.
Flip the hoecakes and cook the other side until golden brown, about 2 minutes more.
Remove from the skillet and drain on paper towels.
Serve hot with butter and/or molasses.