Combine the flour, baking soda, baking powder, and salt together in a medium bowl. Mix and set aside.
In a large mixing bowl, add the eggs, oil, Greek yogurt, buttermilk, sugar, and vanilla extract. Whisk together until smooth. Stir in the dry ingredients and mix until just combined.
Fold the diced peaches into the batter. Let the batter sit while you make the cream cheese filling.
To make the cream cheese filling, beat the cream cheese sugar, and vanilla extract using an electric mixer until smooth.
Place muffin liners in a 12-tin muffin pan. Fill each one about halfway with the batter. Add a little less than 1 tablespoon (divide up between all 12 muffins) of the cream cheese to the middle of each one. Top the muffins with remaining batter. Bake 5 minutes at 400 degrees F, then reduce heat to 350 degrees for 13-15 minutes more or until the batter is set. Let cool and enjoy!