1. Pour oil into a large pot so that it is deep enough for a doughnut to submerge. Insert candy thermometer and turn the heat on high. Carefully monitor this while working on the dough—do not let the oil temperature rise above 375°F.
2. Unroll the refrigerated Puff Pastry Dough onto a cutting board and, using a bowl size of your choice, begin cutting out circle shapes in the dough. A 3.5 in. cutter or bowl is recommended. With each circle, cut a smaller circle (about 1.5”) inside using another circle cutting guide (i.e. a small cup). Save the doughnut holes along with the doughnut circles.
3. Prepare a pan lined with paper towels and topped with a cooling rack, and place near the hot oil.
4. Once the oil reaches 375°F, turn the heat to medium or medium low and add as many doughnuts as will fit without overcrowding. Cook for two minutes, then flip, using a fork or other utensil. Cook for an additional two minutes, then remove to the cooling rack. Check the temperature and adjust it so it stays at 375°F, and cook the second batch. Continue until all the doughnuts and holes are cooked.
5. While doughnuts are cooling, prepare the chocolate sauce. In a small saucepan over low heat, add the chocolate chips, vanilla, and heavy cream. Stir as it begins to melt. Sauce will appear chunky at first, but continue stirring until sauce is creamy and all the chocolate is melted. Remove from the heat and place in a work space near the doughnuts.
6. Working quickly so the chocolate doesn’t harden, dip each doughnut in the chocolate. Once cool enough to eat, serve and enjoy.