Preheat your oven to the temperature according to the directions on your crescent rolls (probably 350-degrees).
Lay the bacon strips onto a baking sheet lined with parchment paper and sprinkle each slice with the brown sugar, as evenly and fully covered as possible.
Bake until the bacon is beginning to brown and crisp, but isn't yet completely done, about 8 or so minutes.
For the Mornay Sauce, place butter in a medium saucepan and cook until melted and bubbling.
Add the flour and stir with a whisk to form a roux, whisking constantly for 2 to 3 minutes (do not let this roux brown).
Pour in the milk all at once, continuing to stir with the whisk while bringing it to a simmer.
Add freshly ground salt and pepper here, while occasionally whisking to test consistency while it continues to cook until smooth and thick; be sure to break up any lumps that form while it thickens.
Once it becomes thick like a gravy, turn off the heat and remove the pan from the stove.
Immediately add the Cheddar and Swiss cheeses while whisking, until melted and well combined.
The cheese will further thicken the sauce to a thick gravy, almost paste. (You can add milk back in if you'd like it thinner. I don't normally.)
Season with salt and pepper again, if needed.
Break a couple pieces of your prepared candied bacon into half or thirds.
Using a basting brush, spread the Mornay Sauce on each crescent triangle, followed by a small slice (perhaps ½ a slice) of the turkey, a piece candied bacon slice, a bit more sauce drizzled on top, and then the shredded Parmesan Cheese.
Fold the two end triangles into one another and begin rolling, being sure to tuck in any ingredients back in that might trickle or fall out.
Once all the crescents are rolled, bake for 8-10 minutes, or until the crescent rolls are puffy and slightly honey brown on top (do not over cook).