In a large bowl, whisk together lukewarm water, granulated sugar, and instant yeast. Let it sit for about 5-10 minutes, or until frothy and bubbly.

In another mixing bowl, combine all-purpose flour and salt. Make a well in the center and pour in the frothy yeast mixture.

Pour in the vegetable oil, eggs, and vanilla extract. Mix until a soft dough forms.

Transfer the dough to a floured surface and knead for about 5-10 minutes until it becomes smooth and elastic.

Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm place for about 1 hour, or until doubled in size.

Punch down the dough gently to release air. Roll it out on a floured surface to about ½ inch thick, then cut out rounds using a donut cutter.

Let them rest for another 30 minutes.

In a deep fryer or large pot, heat oil to 350°F (175°C). Ensure there’s enough oil to fully submerge the donuts.

Carefully place the dough rounds into the hot oil, frying until they are golden brown on both sides, about 2-3 minutes. Drain on paper towels.

Once slightly cooled, use a piping bag to fill each donut with strained strawberry jam. Finally, dust them generously with powdered sugar before serving.