In a small saucepan over low heat, melt the unsalted butter cubes. Once melted, remove from heat and set aside to cool slightly.
In a large mixing bowl, whisk together the milk, vanilla extract, and eggs. Once combined, add the melted butter and mix well.
In a separate medium bowl, whisk together the all-purpose flour, baking powder, salt, and granulated sugar.
Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Be careful not to overmix; a few lumps are perfectly fine.
Gently fold in the mini chocolate chips until evenly distributed throughout the batter.
Preheat your waffle maker according to the manufacturer's instructions. Lightly grease it with non-stick spray or a little melted butter to prevent sticking.
Pour an appropriate amount of batter into the preheated waffle maker (approximately 1/2 to 3/4 cup depending on your model). Close the lid and cook according to the manufacturer's instructions, usually about 4 to 5 minutes, until golden brown and crisp.
Carefully remove the waffles and keep them warm in a low oven while you continue cooking the remaining batter. Serve with your favorite toppings such as maple syrup, whipped cream, or fresh fruits.
