First, bake the peaches. Pre-heat the oven to 400 and get out an 8 x 8 baking dish. Combine the peach slices, brown sugar and cinnamon in it and stir them all together well to coat the peaches. Bake them for 10-12 minutes to make them tender and juicy. Take them out and let them cool for a couple of minutes while you set up a food processor. Pour the peaches into the food processor bowl with the greek yogurt and puree it all together completely until it is a smooth, uniform liquid. Fill 5 popsicle molds to the brim with the liquid and let them freeze for at least 4 hours, or up to overnight. Serve them when they are frozen for a refreshing treat!