In a small bowl combine the lukewarm water and 1 tablespoon of sugar sprinkle the yeast on top and let sit 10 minutes. Stir to combine.
In the bowl of the stand mixer with the dough hook attachment add the flour, remaining sugar, egg yolk and yeast mixture, start to knead on low/medium speed for about three minutes. Add the salt and knead for about 30 seconds then add the softened butter (1/4 cup)* a little at a time, kneading between every addition.
Continue to knead on low / medium speed for about three to four minutes or until the dough is smooth and elastic and pulls away from the sides of the bowl. Place the dough in a lightly greased bowl turning the dough to cover lightly in oil, cover the bowl with a clean tea towel and let rest 40 minutes. Then cover the bowl with plastic wrap and place in the refrigerator for two hours.
Place the butter (3 tablespoons) between two sheets of parchment paper and flatten with either a rolling pin or the palm of your hand, refrigerate for about 15 minutes. Remove the dough from the fridge and let sit for 15 minutes before continuing. Roll the dough into a rectangle about 10 x 7 inches (25 x 18 cm), place the chilled butter in the centre.
Fold the dough into 3 parts like an envelope. Roll the dough again into a rectangle (smaller than the other one) and fold the same way like an envelope.
Refrigerate the dough for about 15-20 minutes. Remove from the fridge and roll into a rectangle 14 x 11 inches (38 x 30cm), sprinkle with the mini chocolate chips.
Tightly roll the dough up lengthwise and cut into 10-11 rolls. Place on a parchment paper lined cookie sheet, cut side up, cover with a clean tea towel and let rise in a warm draft free area for about 2 hours or until doubled in bulk.
Pre-heat the oven to 350F (180C). Bake for about 13-15 minutes. Immediately move to a wire rack to cool, then dust with powdered sugar and serve. Enjoy!
*If dough is too wet then add a tablespoon of flour (you shouldn't need to add more then 2 tablespoons).
Notes
I love chocolate chips so that is what I usually reach for first, although a sprinkling of your favourite chopped nuts would work, or even candied fruit.I know some Italians spread jam, hazelnut cream spread, or chocolate spread or even an Italian Pastry Cream or if you prefer brush the dough with a little melted butter, then sprinkle with a combination of granulated sugar and cinnamon before rolling.If you don’t have enough time to finish the rolls then you can leave the dough in the fridge for up 12 hours. Just be sure to let the dough sit at room temperature for 30 minutes before adding the chilled butter.The buns will be a golden brown on top, I stick a toothpick in the middle of a bun and if it's dry or a couple of crumbs are sticking to it then they are done.The buns should be stored in an air tight container or bag and can keep for up to two at room temperature.Place the completely cooled sweet buns in a freezer safe bag or container, they will keep for up to two months in the freezer. They can be reheated in either the microwave or the oven.