Homemade Buttermilk Donuts

Name: Homemade Buttermilk Donuts
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: American
Ingredients: ¾ cup sugar for donut topping; 2 cups buttermilk OR 1 cup milk + 1 cup plain Greek yogurt mixed together, room temperature; 2 large eggs, room temperature (beaten); 1 ¼ cups sugar; 1 teaspoon baking soda; 1 teaspoon baking powder; 1 teaspoon salt; 1 teaspoon cinnamon; ½ teaspoon nutmeg; 6 tablespoons melted butter; 6 cups all purpose flour (plus more for rolling out); 40 oz canola or vegetable oil for frying