Combine all dough ingredients in mixer. No need to proof the instant yeast. Mix at low speed for five minutes, until smooth.

Remove from mixer and place in a greased bowl. Cover with plastic wrap and refrigerate overnight.

Meanwhile, preheat oven to 300 degrees Fahrenheit.

Line a sheet pan with foil and place tomatoes on the pan. Add oil, herbs, salt and pepper; toss to combine. Roast for about 45 minutes, until tomatoes are blistered.

Remove from oven and cool. Transfer tomatoes to a container and refrigerate until needed.

Remove dough from the fridge and let rest one hour, until room temperature.

Divide into 12 equal pieces. Working with one piece at a time, roll it out to a four- to five-inch circle.

Place two to three marinated tomatoes on dough round and add two tablespoons of shredded mozzarella.

Raise dough edges to form a ball around the filling, rolling gently on a floured surface to shape it. Set aside. Repeat with remaining dough.

Preheat oven to 350 degrees Fahrenheit. Prepare cooling rack over a sheet pan lined with paper towel. Heat three to four inches oil in six-quart stockpot until it reaches 325 degrees Fahrenheit on a deep-fry thermometer. 

Place three to four donuts in the oil and fry until golden, about five to six minutes. Remove from oil and place on the rack. Repeat with remaining donuts.

Place rack and baking sheet in the oven and bake for 10 to 12 minutes until the inside of the donut is cooked through. Serve immediately.