To make the waffles. In a medium bowl whisk together the mashed potatoes, buttermilk, eggs and melted butter until smooth. Stir in the minced sage.
Add the flour, baking soda and baking powder and stir until just combined. Fold in the parmesan cheese.
Preheat waffle iron. When ready scoop the batter (you will need to spread the batter out using the back of a spoon) into the hot, greased waffle maker and cook to your preference. Repeat with the remaining batter. The batter should make about 4-5 waffles, depending on you waffle maker. Tear 2 of those waffles into fourths. If you are using a square waffles just leave them whole.
Prep the sandwiches. Heat a skillet over medium heat and melt the butter. Once hot add the turkey and get it buttery and crisp all over, about 5 minutes. Remove from the heat
Add the avocado to a bowl and lightly mash with a pinch of salt and pepper.
Assemble the sandwiches. Preheat the oven to 425 degree F. Line a baking sheet with parchment and place the waffles on the baking sheet.
Spread the mashed avocado on four of the waffle triangles (or squares or whatever shape you have). Top with sliced brie, then the warm buttery turkey, a dollop of cranberry sauce and two slices of bacon (if using). Now grab the tops to the sandwiches (the remaining four triangles) and add a slice or two of brie. Place the pan in the oven for 5 minutes, watching closely to make sure the brie is not getting too melty! During this time I fried my eggs.
Remove from the oven and top each triangle with one egg and then place the tops on the sandwiches. Push down and eat!! FYI, it is going to be a bit messy. We had to use a fork for these!