Preheat your oven to 375°, and bake the sweet potatoes until they can be easily pierced by a knife. Let them cool slightly so they're safe to handle and peel the skins off and discard.
While the sweet potatoes bake. Char the jalapeño on the grill or open flame of a gas stove until blistered and charred. Pop the pepper into a bowl and cover tightly with plastic wrap for 10 or so minutes. Peel the skin off of the jalapeño, remove the ribs and seeds and dice small.
In a large bowl add in the peeled sweet potatoes and mash. Add in the three tablespoons of butter, 1 tablespoon of maple syrup and the 1/2 teaspoon of kosher salt. Mash until desired texture is achieved. Add in the cream and using a rubber spatula, slowly blend until incorporated. Add in the diced jalapeño, stir.
Add to a saucepan to heat until piping hot and serve.