Turn Blackstone onto high heat and place a small sturdy pan with oil of choice to heat.
In a large bowl mix together ricotta, egg, rum and lemon zest.
In a separate bowl mix together flour, sugar and baking powder.
Slowly add the dry ingredients, ¼ cup at a time, into the wet ingredients and mix to combine. Dough should be thick and sticky.
Using a wooden chopstick or toothpick carefully dip it into the oil, if bubbles appear around the wooden stick oil should be ready for frying (or use a thermometer oil should be perfect between 350-375 degrees)
Using two spoons, slowly drop a ball of dough into the oil. Allow to fry until deep golden brown in color, about 3-5 minutes. If donuts do not flip on their own gently flip donuts for even cooking.
Remove from oil and let drain on paper towels.
Serve with a dusting of powdered sugar.
Notes
Size of donuts should be the size of a ping pong ball. Number of donuts (servings) will depend on the size of donuts made.