Using a dough hook, mix Prima Doughnut Mix and water on low speed for 1 minute. Increase to medium speed for another 9 minutes. Cover the dough and let it rest for 30 minutes at room temperature.
Roll the dough into a rectangle sheet on a floured surface. Fold ⅓ of the rectangle towards the center then fold the other end towards the center, rest for 10 minutes. Turn 90 degrees and repeat the step.
Divide dough into rounds without punching out the middle hole. Cover and let it rest for 1 hour at room temperature
Heat oil to 180°C and deep fry doughnuts until golden brown. Set aside to cool before decorating.
Cut a slit at the side of the doughnut and pipe in the strawberry jam.