1. Adjust the oven rack to the middle position and preheat the oven to 350 degrees Fahrenheit. Line a baking sheet with Gefen Parchment Paper or spray two eight- or nine-inch loaf pans with baking spray.
2. For the filling, mix brown sugar and cinnamon together.
3. For the crumb topping, rub the flour, sugar, and fat with your fingertips until crumbly.
4. Divide dough in half. Roll one half on a clean work surface into an eight- or nine-inch square. Brush oil over the dough, then spread half the filling over the dough to within a half inch of the border. Fold the right and left sides over about half an inch, then roll up the dough away from you, using a bench scraper to loosen dough if needed. Pinch the seam together, and place the roll seam-side down on the prepared baking sheet or in a prepared loaf pan. Repeat with the second piece of dough.
5. Brush the tops with oil and sprinkle with crumbs. Bake for 30 minutes, rotating the pan(s) halfway through baking, until puffed and light golden brown. (The loaves will split down the center as they bake.)
6. Cool completely in the pan and slice to serve.