Step 1In the bowl of a stand mixer fitted with a paddle attachment, combine the flour, yeast, one-half cup sugar and salt. Add the vegetable oil and mix at a low speed to combine.
Step 2Fill a liquid measuring cup with 1 cup warm water. With the mixer speed on low, start adding the water slowly -- just enough for the dough to come together (we used just shy of 1 cup water), neither too wet nor too dry. Continue to mix at medium-low 2 to 3 minutes until the dough is evenly combined and smooth. Be careful not to overmix. Cover the dough with plastic film and allow to rise until doubled, 2 to 3 hours.
Step 3Heat the oven to 350 degrees (for either a convection oven or regular oven). Divide the dough in half and place one half on a floured work surface. Flatten it gently with the palm of your hand to a general rectangle shape; continue flattening it with a rolling pin until the rectangle is about 18 by 10 inches. Do not worry if the dough bubbles slightly while it is rolled out. Brush 5 to 6 tablespoons of tahini paste all over the rectangle to get a thin layer and then sprinkle 4 tablespoons sugar over the tahini.
Step 4Roll the rectangle up lengthwise and trim the ends. Cut the roll into 1- to 1 1/4 -inch lengths; you will have 12 to 16 pieces. Place each piece between your hands, cut sides against your palms; press to flatten into a disc (they will look like rosettes).
Step 5Place the discs on a parchment-lined cookie sheet and bake until deep golden brown, about 15 minutes in a convection oven or 18 to 20 minutes in a regular oven, rotating the cookie sheet halfway through. Repeat with the remaining half of the dough.