Poke a few holes in the potatoes with a fork and arrange on a baking sheet. Bake for 45-50 minutes until cooked through and fork tender.
Allow to cool for a few minutes. Remove the skin by peeling off with your hands.
Place the peeled potatoes in a large bowl and set aside.
In a small saucepan, melt the butter over medium heat and continue cooking until the butter starts to brown, approximately 10-12 minutes. Stir occasionally.
Pour the butter over the potatoes.
Add the mascarpone cheese to the potatoes. Beat the mixture with a hand mixer until smooth and creamy.
Season with salt and pepper, to taste.
Serve immediately.
Notes
Potatoes can be made up to 24 hours in advance and stored in the refrigerator in an airtight container. To reheat, transfer to a microwave safe bowl and heat for 4-5 minutes, stirring after each minute until heated through. Or transfer to an oversafe dish and heat in a 325 degree oven until heated through.