Mix together 4 large eggs, 1 cup granulated sugar, and 1 tsp vanilla extract until combined.

Add 1 cup unsalted butter, stir to combine. Add 4 Tbsp all-purpose flour & 2 tsp baking powder. Mix thoroughly to combine. Rest covered for 1 hour.

Meanwhile, line a large baking sheet with parchment paper. Set aside.

After 1 hour - Preheat oven to 350F with the rack centered.

Add 3 ½ cups all-purpose flour into the runny dough we prepared earlier and mix thoroughly.

Shape: Pinch away a piece of dough the size of a large cherry, or use a #60 scoop to scoop 15 g of dough and roll it into a ball.

Flatten slightly on the tray and leave about 1 inch (2-3 cm) between each ball. You can oil or water your hands to prevent sticking.

Bake for 10-12 minutes at 350F. The cookies should remain fairly pale on top, with the bottoms lightly golden.

Continue shaping the rest of the dough while the first batch is baking. Then bake the second batch when the first one is out of the oven.

Cool the cookies until you can hold them in your hand.

Cup the cookie in the palm of your hand, bottom up. Using a melon baller or a teaspoon, hollow out the center to make room for the filling. Scoop until the shell is about 1/4 inch thick.

Keep the cookie scraps for something else, we won't need them for this recipe.

Whip butter: With a mixer fitted with a whip attachment, whip 8 oz unsalted butteruntil white and fluffy, about 2-3 minutes. Make sure to scrape the bottom of the bowl throughout the process.

Add 1 can Dulce de Leche / cooked sweetened condensed milk & 1 tsp vanilla extract,and whip again, until well combined, about 1 minute.

Fill the cookies:

Pair the cookies by size.

Fill each half with the filling, slightly overfilling so the two halves stick together. Add 1 hazlenut to one of the halves. Press the two filled halves together. Wipe off any extra cream.

Prepare the sugar: Add 1 cup sanding sugar to a bowl.

Make the colors: You'll need 2 small bowls, each filled with 1 cup of water, to dip the prepared cookies into.

Add 1 cup of water into each bowl. Add Yellow Food Coloringto one bowl and Red to the other. Stir to dissolve...

Dip: Quickly dip the whole cookie into the yellow ‘cup’ and then only half of the cookie into the red. They should now resemble a peach in color. Dab lightly against a folded paper towel to absorb any extra liquid.

Roll in the sparkling sugar. Place on the tray.

Leave at room temperature for a couple of hours. This lets the moisture redistribute evenly throughout the cookie while the outside dries. Do not leave in a closed container, or the cookies will become soggy.

Then refrigerate - line a container with a paper towel and add the cookies in a single layer. Cover with a lid and refrigerate.

Garnish: Right before you serve the cookies, insert the hearts of Mint Leaves to make them look like real leaves from peach trees.