Preheat the oven to 375 degrees F (190 degrees C). Spray a fluted tube pan (such as Bundt®) with butter-flavored cooking spray.
Mix white sugar, brown sugar, cinnamon, and nutmeg together in a bowl.
Open the refrigerated cinnamon rolls. Divide rolls by package, then cut into quarters with a pizza/dough cutter.
Place each package of cut cinnamon roll pieces in the sugar mixture and toss until covered, keeping them separated. Do not discard excess sugar mixture.
Layer each separate portion of sugar-coated cinnamon roll pieces in the bottom of the prepared pan, sprinkling with pecans as you go, ending with pecans on top.
Combine excess sugar mixture with 3/4 cup of butter in a saucepan over medium-low heat; bring to a boil. Pour butter mixture over the cinnamon roll pieces.
Bake in the preheated oven until the top is crispy, about 40 minutes. Remove and allow to cool for 10 minutes.
While cooling, mix confectioners' sugar, lemon-lime beverage, oats, and remaining 1/2 cup of room temperature butter together for icing.
Remove the bread from the Bundt® pan, then drizzle the icing over the bread to taste.