Preheat the oven to 350 degrees. Melt 1 tablespoon butter in a small, microwave safe dish. Spread the pear slices out onto a sheet pan, drizzle with the melted butter, and toss gently to coat. Roast the pears for 15-20 minutes or until just tender. While the pears are roasting, fill a large pot with 4 quarts of water plus 1 tablespoon of salt. Cover and place over high heat to boil.

To toast the pine nuts, place them into a small sauté pan over medium-low heat and stir frequently until lightly browned, about 5 minutes. Set aside until ready to use.

When the pasta water boils, cook the penne according to the package instructions. Drain the pasta and return to the dry pot. Add the remaining 2 tablespoons butter, cinnamon, feta, and pine nuts. Stir together to melt the butter and combine the ingredients. Lastly, gently stir in the still-warm roasted pears. Transfer the pasta to a platter or bowl and sprinkle with a few pinches of cinnamon to garnish.