Preheat the oven to 400°F. Place 1 tablespoon butter in a 10-inch iron skillet and set it in the oven for about 5 minutes to melt the butter and heat the skillet.
In a large bowl, stir the sugar into the Bisquick with a fork.
Stir in 1 1/2 cups shredded cheddar, reserving a little extra cheese for the top.
In a separate bowl, beat the egg into the milk for 35 to 40 seconds, until bubbles form on top.
Pour the milk mixture into the dry ingredients and stir with a spatula just until combined, about 12 to 15 turns. Do not overmix.
Carefully remove the hot skillet from the oven. Pour the batter into the melted butter and spread evenly.
Sprinkle the reserved cheese over the top. Bake at 400°F for 17 to 25 minutes, until golden. Check early; ovens vary.
While the bread bakes, melt 4 tablespoons butter and stir in the garlic powder, parsley flakes, and onion powder.
Pour the garlic herb butter over the hot bread and brush it over the entire top. Slice into wedges and serve warm.