Mix flour, baking powder, and salt together in a large bowl.
Combine water and canola oil in a separate bowl. Mix into the flour mixture with a fork until dough forms a ball, adding 1/4 cup water if dough is too dry.
Knead dough until smooth, 3 to 4 minutes. Divide into 14 egg-size balls. Cover bowl with a cotton towel. Let dough rest for 10 to 15 minutes.
Roll 1 ball dough into an 8-inch tortilla on a floured work surface. Repeat with remaining dough.
Preheat an ungreased cast iron griddle on medium-high heat. Place 1 tortilla on the hot griddle; cook until browned spots form, about 1 minute per side. Transfer to a plate; cover with a cotton towel to keep warm. Repeat with remaining tortillas, stacking them under the towel.