Following these detailed steps will help you achieve flaky layers and a juicy filling for your Irresistible Peach Pie Cruffins:

1. Prepare the Peaches: In a bowl, combine the diced peaches, brown sugar, cinnamon, corn starch, and vanilla extract. Mix well and set aside for flavors to meld.

2. Make the Dough: In a large mixing bowl, combine flour, sugar, baking powder, baking soda, and salt.

3. Cut in Butter: Add the cubed cold butter to the dry ingredients. Using a pastry cutter or your fingers, mix until the mixture resembles coarse crumbs.

4. Add Buttermilk: Gradually incorporate the buttermilk into the flour mixture until it forms a dough. Be careful not to overmix.

5. Chill the Dough: Cover the dough with plastic wrap and refrigerate for at least 30 minutes. This will help achieve flaky layers.

6. Roll Out the Dough: On a floured surface, roll out the chilled dough into a rectangle about 1/4-inch thick.

7. Add Filling: Spread the peach mixture evenly over the rolled-out dough.

8. Fold and Roll: Starting from one end, carefully roll the dough into a log. Cut the log into 12 equal pieces.

9. Shape Cruffins: Take each piece and place it into a greased muffin tin, standing it upright. Gently press down to fit.

10. Preheat the Oven: While arranging the cruffins, preheat your oven to 375°F (190°C).

11. Brush with Egg: Beat the egg and use it to brush the tops of each cruffin for a beautiful golden color.

12. Bake: Place the muffin tin in the preheated oven and bake for 25-30 minutes, or until the tops are golden brown.

13. Cool: Once baked, remove from the oven and let them cool in the pan for about 15 minutes before transferring them to a wire rack.

14. Optional Topping: For an extra indulgence, sprinkle some sugar on top while still warm.

By following these steps, you’ll create Irresistible Peach Pie Cruffins that are sure to impress everyone with their deliciousness!