Prepare instant coffee and hot water mixture and let it cool. In a bowl, whisk together Egg yolks, Sugar. Beat until the mixture becomes pale, thick, and creamy (about 3-5 minutes). Gently whisk the mascarpone into the yolk mixture until smooth. Add 2-3 tsp of instant coffee mixture and mix everything together.

Don't overmix - mascarpone can split if worked too much.

Whip the cream In a separate bowl. Whip to soft-medium peaks.

Fold the cream into the mascarpone mixture. Cover it and refrigerate it for good couple of hours.

In a mixing bowl, combine bread flour, cake flour, sugar, salt, and yeast. Add the egg + milk mixture. Mix until a rough dough forms. Add the softened butter and continue kneading until the dough is smooth, elastic, and slightly tacky. Place in a lightly oiled bowl, cover, and let rise for 1-1.5 hours or until doubled.

Punch down the risen dough and make balls each weighing about 74-75g. Place on parchment-lined trays, cover, and let rise for 35-45 minutes until puffy.

Heat oil to 160-165°C (medium heat). Low heat helps them cook evenly and stay light.

Fry 1-2 pieces at a time. Do not overcrowd.

Cook each side for 2-3 minutes until golden. Let them cool down.

Fit a piping bag with a medium round tip and fill the piping bag with the prepared filling.Poke a small hole on the side of each bombolone and fill in with caramel.

Carefully cover it with cocoa powder and sugar mixture.