Heat the oven to 400°F. Grease the sides and bottom of a 8 or 9″ baking pan with cooking spray.
Combine the ricotta cheese, buttermilk, sugar, melted butter, and vanilla in food processor and process until smooth, about 10 seconds.
Add the flour, baking powder, salt, and baking soda and pulse in short bursts just until the dough clumps together (don’t overprocess). The dough will be soft and moist.
Dump the dough out onto a lightly floured surface and knead it with floured hands 4 or 5 times until smooth (it really only takes 4-5 times). With a rolling pin, roll the dough into a 12×15-inch rectangle. I discovered that 12×15 is exactly the size of my flexible plastic cutting board, so that’s a quick and easy way to size it.
Brush the dough with the melted butter, leaving a 1/2-inch border unbuttered around the edges. In a medium bowl, combine brown sugar and spices. Sprinkle the mixture over the buttered area of the dough and press gently into the surface.
Starting at a long edge, roll up the dough jelly-roll style. Pinch the seam to seal, and leave the ends open.
With a sharp knife, cut the roll into equal pieces (I got 8). Set the pieces, cut side up, in the prepared pan; they should fill the pan and touch slightly, but don’t worry if there are small gaps.
Bake until golden brown and firm to the touch, 20 to 28 minutes. Set the pan on a wire rack to cool for 5 minutes. Run a spatula around the inside edge of the pan to loosen the rolls, and transfer them to a serving plate.
In a small bowl, mix the softened mascarpone cheese, powdered sugar, and vanilla to make a smooth glaze. Add milk as needed to achieve desired consistency. Spread or drizzle onto warm rolls. Let stand 10 minutes (or as long as you can stand) and serve.