Tip: If you kitchen is cold, then if your oven can, pre-heat the oven at 30ºC while the eggs and butter reaches room temperature. Then turn off the oven, keeping the oven door closed, right before making the dough. This way you can rise your dough in the turned of oven giving it the optimal temperature of between 23-25ºC.
Melt the butter and mix it together with lukewarm water. The temperature once mixed together should be around 37ºC. Crumble the fresh yeast into your mixing bowl and pour in the butter/water mixture. With a spatula stir it together until the yeast has melted.
50 g butter, 25 g fresh yeast, 110 g lukewarm water
(If you are use dry yeast, let it bloom in the warm milk per instruction of the pack)
Add all of the remaining ingredients, starting on 290 g of flour. Add later, if needed, the remaining 15 g of flour.
25 g granulated sugar, 290-305 g all-purpose flour, 1 eggs, ½ teaspoon salt
Using the dough hook, mix and knead the dough for 8-10 min on medium/high speed or until the dough looks smooth and has collected and is releasing from the bottom. The dough should be tacky but not stick to your fingers.
Add the dough to your counter top and give it a final kneading and shape it it to a nice loaf. Add the dough to a bowl with a bit of flavour neutral oil and cover the bowl with cling film and a tea towel.
Place it in a warm room temperature area in your house or use the trick with the oven. Let it rise for 45 min.
After the 1st rise, place the dough on the counter top. Try and not use any flour on the counter. If needed add a bit of flavour neutral oil on the kitchen counter instead. Roll the dough into 1 cm thick circle and cut out the donuts with a 7 or 8 cm cookie cutter. Save the remaining dough for donut holes.
Cut baking paper into about 10x10 square and place each donuts on a square. Cover the donuts with cling film and a tea towel and let them rise for a second time on the kitchen counter for 30-45 min. They are finished proofing when you can poke them lightly with your finger and it leaves a small indentation that springs back.
While the donuts rises for the second time, slowly heat up the flavour neutral oil in a large heavy-bottomed pot to around 180ºC (+/- 5ºC).
Flavour neutral oil
Place a wire rack over some paper towel and place the granulated sugar in a shallow bowl.
Gently lower one donut at a time into the oil. Frying 2 at a time in the oil and use some tongs to carefully remove the baking paper. Fry the donuts for 2 min on each side and golden brown.
Check the temperature of the oil regularly as you go, to not let the oil get too hot or too cool.
Once the donuts are fried, place them one the wire rack while adding the next two donuts into the oil. Then place one donut at a time into the granulated sugar and toss each donut until well coated. Then place the donut back on the wire rack until cooled down before filling them with the blackberry cheesecake filling.
150 g granulated sugar