In a large mixing bowl, combine the all-purpose flour, instant yeast, sugar, and salt. Pour in the warm milk and melted butter, stirring gently until a dough forms.

Transfer your dough to a lightly floured surface and knead for about 5-7 minutes until it's smooth. Cover it with a damp cloth and let it rise in a warm place until it doubles in size, roughly 1-2 hours.

Roll the dough into a rectangle, spreading a layer of butter over two-thirds of it. Fold the dough like a letter, and roll it out again. Repeat this process twice, chilling in the fridge between rolls as needed.

Once the dough is layered and chilled, roll it out to about 1/2 inch thick. Use a donut cutter to cut out circles. Allow the cut dough to rise until puffy, about 30-45 minutes.

Heat oil in a deep skillet to around 350°F. Carefully fry each Cronut until golden brown, about 2-3 minutes per side. Drain them on paper towels to absorb excess oil.

Using a piping bag, inject your desired filling into the center of each Cronut. While they are still warm, dip the tops into your prepared glaze for that irresistible shine.

Optional: Dust with powdered sugar before serving for an extra special touch.