Preheat the oven to 425 degrees. Coat a muffin pan with cooking spray.
Prepare the muffin batter whisking together the sugar, oil, sour cream, eggs, and almond extract together until well creamy and smooth.
In a separate dish whisk the flour, baking powder, baking soda, and salt together until well combined.
Slowly add half of the flour mixture to the batter until just combined. Add the diced nectarines and blueberries; gently mix. Pour the batter equally into the muffin pan filling them to the top.
Sprinkle the almonds equally followed by some coarse sugar on top of each muffin.
Place into the oven and bake for 5 minutes. Reduce the heat to 350 degrees and continue to cook for 13-15 minutes, or until a tester inserted in the center comes out clean.
Remove from the oven and cool in the pan for a few minutes before putting them on a wire rack over parchment paper to finish cooling.
Serve and enjoy.