In a large bowl, mix water, sourdough starter, oil, flour, salt, and baking powder until combined.
Knead for 2–3 minutes in a stand mixer or about 5 minutes by hand until smooth.
Cover the dough and let it rest for 30 minutes at room temperature.
Divide the dough into 40g pieces and roll each into a ball. Cover and rest for 15 more minutes.
Preheat a skillet on medium-high heat.
Roll each ball into a thin circle.
Cook each tortilla for 30–45 seconds per side, flipping when bubbles appear.
Stack cooked tortillas in a clean kitchen towel to keep soft.
Serve warm or store for later. They can be frozen once cooled.
