Prepare the ramekin: Lightly grease the inside of the ramekin with butter or non-stick spray.
Mix the dry ingredients: In the ramekin, whisk together the flour, brown sugar, baking powder, and a small pinch of salt.
Add the wet ingredients: Stir in the milk, melted butter, vanilla extract, and caramel sauce (optional) until the batter is smooth and well combined.
Add caramel chips: Fold in caramel chips for an extra caramel boost.
Microwave: Microwave on high for 60-90 seconds. Start checking at 60 seconds to avoid overcooking. The cake is done when the top is set and a toothpick inserted in the center comes out clean.
Cool: Let the cake cool for 1-2 minutes.