Add butter to a small skillet melt over medium heat. Once melted, stir occasionally until butter darkens and smells nutty and toasted, around 10 minutes. Remove from heat and transfer to a heat-proof container. Stir in the honey, vanilla, cinnamon and nutmeg and set aside.
Preheat Cuisinart 360 Griddle Cooking Center to medium-high one side and medium-low on the other. Butter toast slices and cook on the medium-low side until browned and crisp, around 2-3 minutes per side. Sprinkle with cinnamon sugar and let cool, then break into crumbs by hand or by pulsing in a food processor. Set aside.
Brush the medium-hot side of the griddle with a neutral oil, then add the pear halves, cut-side down and roast, untouched for 3-4 minutes, or until dark brown and just beginning to blacken at the edges. Flip and cook the skin-side for an additional 3-4 minutes. Remove from heat.
Drizzle browned butter over each roasted pear half, smear with a dab of mascarpone, then sprinkle generously with the cinnamon toast crumbs. Serve immediately. Store excess browned butter in an air-tight container in the fridge.