Preheat the oven to 400°. Prick potatoes all over with with a fork, place directly on the rack of the oven and roast for 50-60 minutes or until tender and cooked through.
Carefully slice off the top quarter of each potato and allow to cool slightly for about five minutes. Scoop out the flesh of each potato into a large bowl being careful to leave behind a 1/4 inch layer of potato on the inside to form a shell. Brush each shell inside and out with the melted butter and sprinkle the insides with 1/4 teaspoon of salt.
Raise the heat of the oven to 475°. Place the buttered potato shells on a baking sheet fitted with a wire rack and roast in the oven for 15 minutes, or until they begin to crisp.
While the potato shells are baking in the oven mix the half-and-half with 1/2 of the cheese. Cook the remaining butter and garlic in a small saucepan over medium-low heat until garlic is lightly golden and aromatic, about 3-5 minutes. Add the half-and-half/cheese mixture to the garlic butter and mix thoroughly. Heat until just warm.
Press the reserved potato flesh through a ricer or food mill and gently fold in the warm cheese/butter mixture, remaining salt and pepper until well combined.
Remove the potato shells from the oven and fill them with the potato-cheese mixture. Carefully spread on the remaining cheese and bake for 15 minutes, or until warmed through and golden brown.
Sprinkle with chives and bacon bits and serve immediately.