1. Make the Yeast Mixture:

• In a bowl, combine lukewarm milk, water, yeast, and sugar.
• Stir well and set aside for 10 minutes until foamy.

Tip: Ensure the milk and water are between 30-35°C (85-95°F) for optimal yeast activation.

2. Prepare the Dough:

• In a stand mixer with a dough hook (or use a hand-held electric mixer with dough hooks), combine flour, eggs, egg yolk, rum (if using), salt, and the yeast mixture.
• Knead on low speed, then increase to medium and knead for 6-8 minutes until smooth and elastic.
• Add the butter and continue kneading for 3-4 more minutes until incorporated.

3. First Proofing:

• Cover the dough with clingfilm and let it rise at room temperature (20-25°C / 68-77°F) for 1 hour, until visibly increased.
• Transfer to the fridge for 30 minutes to make shaping easier.

4. Shape the Beignets:

• Lightly flour a large baking sheet.
• Roll the dough into a 20cm x 60cm (8 x 24 inch) rectangle.
• Cut into 16 triangles, each about 8cm x 25cm (3 x 10 inch).
• Roll each triangle into a croissant shape, starting from the thickest end.
• Place on the baking sheet, cover with a damp kitchen towel, and let rise for 1-1.5 hours until tripled in size.

Tip: The croissants should jiggle slightly when the baking sheet is shaken after proofing.

5. Fry the Beignets:

• Heat oil in a deep pan to 170-180°C (340-355°F).
• Lightly dust a spatula with flour, pick up a beignet, and gently drop it into the oil with the seam side up.
• Fry 3 minutes covered, then flip and fry 3 more minutes uncovered.
• Transfer to a paper towel-lined wire rack. Repeat with the remaining dough.

6. Coat & Fill:

• In a bowl, mix sugar, powdered sugar, and cinnamon.
• Roll the warm beignets in the sugar mixture to coat.
• If filling, make a small incision in the bottom and pipe in chocolate spread using a pastry bag.

7. Serve & Enjoy!

• Serve warm, dusted with extra powdered sugar if desired.