Place the dry ingredients (flour, salt, baking powder) in a large bowl and mix well.

Add the oil.

Rub the oil into the flour mixture until well combined.

Add the cup of water.

Mix well until a soft, elastic dough forms that doesn't stick to your hands. Let the dough rest for 5 minutes.

Prepare the cornstarch for rolling out the dough on your work surface.

Divide the dough in half. Take one half and sprinkle cornstarch on your work surface and on top of the dough.

Roll out the dough with a rolling pin.

Once you have a large, round sheet of dough, gently lift it from the work surface (it will be thin and delicate) and sprinkle a little more cornstarch underneath. Flip the dough over and roll it out again until it's very thin, similar to phyllo dough.

After flipping and rolling out the dough again,

Check the thinness of the dough. (You can roll it even thinner if desired.)

Cut the dough into long rectangles.

Take a rectangle and brush it with melted butter or ghee (optional). (If the rectangle is too long, you can cut it in half so it fries better and cooks through, as thicker dough may not cook well inside.)

1/4 cup melted butter or ghee.

Remove excess butter or ghee from the brush by wiping it on the edge of the cup.

Brush the dough as described.

Add your desired filling and fold the rectangle into a triangle shape to form sambusa.

Alternatively, after rolling out the dough and cutting it into rectangles, you can cut them crosswise and roll them up with filling to make rolls or fingers, as shown in the picture.

Note: Use cornstarch instead of flour for rolling out the dough, as cornstarch prevents the sambusa from absorbing too much oil during frying, unlike flour, which can make them greasy.