Spread prepared peaches in single layer on paper towel–lined baking sheet and pat thoroughly dry with paper towels.
Combine flour, brown sugar, baking powder, salt, cinnamon, and nutmeg in large bowl.
Whisk milk, eggs, melted butter, and vanilla extract in medium bowl until combined. Stir in peaches into flour mixture. Then add milk mixture into dry ingredients.
Heat oil in Dutch oven over medium-high heat to 350 degrees. Use 1/3-cup measure to transfer 5 heaping portions of batter to oil. Press batter lightly with back of spoon to flatten. Fry, adjusting burner as necessary to maintain oil temperature between 325 and 350 degrees, until deep golden brown, 2 to 3 minutes per side. Transfer fritters to wire rack set inside rimmed baking sheet. Bring oil back to 350 degrees and repeat with remaining batter. Let fritters cool 5 minutes.
Meanwhile, whisk confectioners’ sugar, nectar, cinnamon, and nutmeg in medium bowl until smooth. Top each fritter with 1 heaping tablespoon glaze. Let glaze set 10 minutes. Serve.
Be sure to dice the peaches super small. It allows the fruit to melt into the dough.