Mix dry ingredients: Whisk together flour, salt, and baking powder in a large bowl.
Add wet ingredients: Add hot water and melted butter and mix until a rough shaggy dough forms.
Knead: Knead on a lightly floured surface until smooth and supple, 6-8 minutes by hand or 2-3 minutes in a stand mixer on low. Do not over-knead.
Rest: Cover and rest for 30 minutes.
Portion: Divide into portions based on size — 150 g for burrito-size. Roll into smooth balls and keep covered.
Roll: On a lightly floured surface roll each ball from the center outward, rotating 45 degrees after each pass, until about 14 inches in diameter. Flour lightly as needed.
Cook: Cook on a hot comal or skillet over medium-high heat until bubbles form and light brown spots appear. Flip and cook until puffed. Do not overcook.
Stack and cover: Stack immediately and cover with a clean kitchen towel to keep soft and pliable.