Follow these clear steps to create your homemade cronuts:

1. Make the Dough: In a large bowl, combine all-purpose flour, bread flour, sugar, salt, and instant yeast.
2. Add Wet Ingredients: Pour in the warm milk, warm water, melted butter, and egg. Mix until a soft dough forms.
3. Knead the Dough: Transfer the dough to a floured surface and knead for about 5-10 minutes until smooth. Form it into a ball and place it in a lightly greased bowl.
4. First Rising: Cover the bowl with plastic wrap or a clean towel, and let the dough rise in a warm place for about 1 hour or until doubled in size.
5. Prepare the Butter Block: While the dough rises, place the cold unsalted butter between two sheets of parchment paper and pound it into a flat rectangle, about 8×6 inches. Chill in the fridge until firm.
6. Roll the Dough: Once risen, punch down the dough and roll it out into a rectangle about 12×24 inches on a floured surface.
7. Incorporate the Butter: Place the cold butter block in the center of the rolled dough. Fold the dough over the butter, enclosing it completely.
8. First Fold: Roll the dough out to a rectangle again, about 12×24 inches. Fold it into thirds like a letter. Wrap in plastic and refrigerate for at least 30 minutes.
9. Second Fold: Repeat the rolling and folding process two more times, chilling the dough for 30 minutes between each fold.
10. Cut the Doughnuts: After the final chill, roll the dough out to about 1/2 inch thick. Use a doughnut cutter to cut out doughnut shapes, or use two round cutters of different sizes to make cronuts.
11. Final Rise: Place the cut cronuts on a parchment-lined baking sheet. Cover with a towel and let them rise for about 30 minutes.
12. Heat The Oil: In a deep pot or fryer, add oil, and heat it to 350°F (175°C).
13. Fry the Cronuts: Carefully place a few cronuts into the hot oil, frying until golden brown, about 2-3 minutes per side. Remove them with a slotted spoon and drain on paper towels.
14. Coat in Sugar: While still warm, roll them in sugar or glaze them with your choice of icing.
15. Fill and Enjoy: If desired, fill the cronuts with custard, jam, or chocolate using a piping bag.