In a bowl, mix the whole milk, active dry yeast, and sugar. Let the mixture activate for about 5 minutes until bubbly and creamy.

In a mixing bowl, cream the salted butter and white sugar until light and fluffy. Then, add the eggs and vanilla, mixing until smooth.

Gradually mix in the bread flour, all-purpose flour, cocoa powder, dry milk powder, and sea salt until a soft dough forms.

Turn dough onto a floured surface and knead until smooth and elastic, about 5-7 minutes. Place in a greased bowl to rise until doubled, about 1 hour.

Once risen, roll out the dough to about ½ inch thick. Use a donut cutter to cut out donuts and let them rise again for 30 minutes.

Heat oil to 350°F (175°C). Fry donuts for 2-3 minutes on each side until golden brown.

Heat 1 ¾ cups of whole milk in a saucepan. Whisk egg yolks, sugar, cornstarch, cocoa powder, fine espresso powder, and a pinch of salt in a bowl.

Once the milk is hot, slowly whisk it into the egg mixture. Return to saucepan and cook over medium heat, stirring constantly, until thickened.

Remove from heat and stir in the good quality chocolate, unsalted butter, and vanilla until smooth. Cool in the fridge.

After the donuts have cooled, fill each with the cream filling using a piping bag.

Mix white sugar with fine espresso powder and sprinkle over filled donuts before serving.