Preheat oven to 400°F. and line a baking sheet with parchment paper. Set aside.

Combine flour, sugar, baking powder, salt and cinnamon in a large bowl. Add very cold small butter chunks. Use pastry blender to cut in butter until it's reduced to the size of peas. NOTE: Use a food processor if desired. Pulse butter and dry ingredients several times until butter is size of peas.

Peel/chop fresh peaches into small pieces. Place on paper towels; blot gently to remove excess juice. Add peaches to dry ingredients; gently stir until combined.

In separate bowl, whisk sour cream, one egg and vanilla extract well. Once combined, add this to the peach mixture; gently stir until combined (don't overmix). Dough will be fairly "moist and tacky" in texture.

Transfer dough onto a floured work surface. Sprinkle additional flour onto dough, as needed, to remove the stickiness. Knead dough gently (5-6 times) with floured hands, adding additional flour as needed to bring dough together. Shape dough into a circle about 8" wide.

Carefully cut dough into 8 wedges with a knife. Reshape as needed (due to the moist dough). Place them on parchment lined baking sheet in a circle, leaving ¾"-1" inch between each wedge. While scones bake, they expand, rise and bake together, so the little space in between disappears.

Bake at 400°F. for 18-20 minutes (check them at 18 minutes). When done, scones should be cooked through/golden brown on top. A toothpick inserted into a scone should come out free of batter. Let scones cool a few minutes, then separate them with a knife. Transfer scones to a wire rack to cool completely. Place parchment paper UNDERNEATH rack to catch drips while glazing scones.

In a small bowl place powdered sugar, vanilla and mashed peach half (mash peach well with flat side of a meat mallet or a fork). Stir to combine. Mashed peach will turn mixture into a more liquid form. The glaze should be not too thin OR thick, but "paintable" so it can be easily brushed onto the cooled scones. Too thin? Add a bit more powdered sugar. Too thick? Add a drop or two of water.

Once scones have cooled to room temperature, it's time to glaze them! Use a pastry brush to brush icing on each one, lightly covering surface. After glazing scones, if you have any icing leftover, go back and brush it on any missed parts. Let glaze harden slightly, then serve and enjoy the scones!