Heat your waffle iron to high heat.

Combine flour, baking powder, salt, and sugar in a medium bowl.

Melt the butter in the microwave in a large measuring cup. Add the buttermilk to the hot melted butter mixture and whisk together. Whisk in the egg and vanilla.

Add the wet ingredients to the dry ingredients and stir until just combined. The batter will be a little lumpy.

Pour batter into the heated waffle iron until it just covers the outside edges (always better to err on the side of too little batter rather than HUGE mess on your counter).

Remove waffles when they're browned and crispy on the outside and place in a single layer on a baking sheet. I got 6 waffles out of this batter, which will make 12 sandwiches. If you don't want that many sandwiches, you can wrap the extra waffles in saran wrap, place in a freezer safe bag, and save them for breakfast another day.

Preheat the oven to 300 degrees.

Break the waffles into fourths. Smear cream cheese all over one side of the waffles, then spread cranberry sauce on top of that. Place slices of turkey on the cranberry sauce followed by the arugula. Top with another quarter of a waffle, then place the sandwich back on the baking sheet.

Repeat with remaining sandwiches. Place the sandwiches in the preheated oven for about 10 minutes or until warmed through. Sprinkle with sifted powdered sugar, if desired, then serve.