Cook elbow macaroni according to package directions, drain well. Set aside.
Add butternut squash to a food processor or blender & puree until smooth. Add 1/2 cup of water & blend again. Set aside.
In a large skillet or saucepan over medium heat, add the butter.
When butter is melted, add your gluten free flour & whisk. Add nutmeg.
Cook for 3-5 minutes, whisking constantly.
Add your water/sour cream mixture, and whisk until smooth. T
urn heat to high & bring to a boil while continuing to whisk. After your sauce has thickened, turn heat to low & then whisk in your butternut squash mixture.
Stir in fresh rosemary.
Add cooked elbow macaroni to the pan & then stir until noodles are well coated. Turn off heat.
Season with salt & cayenne (to taste).
Prepare your gluten free breadcrumb* topping by stirring in a pinch of rosemary, a pinch of salt & a dab of melted butter into your breadcrumbs & then tossing to coat. Set aside.
Preheat oven to 400° F.
Grease a casserole dish (I used a round 8").
Pour half of the macaroni noodles mix into the pan.
Sprinkle half of the sharp cheddar/parmesan mix over the noodles.
Add the remaining noodles & then top with the rest of the cheese mix.
Sprinkle your prepped breadcrumbs on top.
Place your pan in a 400° F oven & bake for 30 minutes, or until bubbling & beginning to brown.
Remove from oven & let it sit for a few minutes before serving. Enjoy!