Preheat oven to 450°F. Pour melted butter into a 9x13-inch baking dish and spread it evenly.
In a large bowl, whisk together flour, baking powder, sugar, garlic powder, and salt.
Stir in shredded cheese and chopped ham until well combined.
Add buttermilk and stir until just combined; do not overmix.
Pour the biscuit batter into the buttered baking dish and spread it evenly.
Use a knife to cut the unbaked dough into 12 squares.
Bake for 25-30 minutes, or until the top is golden brown and a toothpick comes out clean.
Let cool for a few minutes before serving. Enjoy warm!