Preheat the oven to 325. In a medium saucepan, melt the butter. Add the brown sugar and stir until dissolved, then add the walnuts. Toast the walnuts for about three minutes, ensuring they’re well coated in the caramel mixture. Pour out onto a piece of wax paper and put in the refrigerator to harden.
Without rinsing out the plan, place the thinly sliced onions into the leftover butter mixture and sautee until caramelized, about 15 minutes. Set aside.
Set up your pizza assembly station. Onto each piece of flatbread, spread half a cup of apple butter. Arrange the apple slices over top, then sprinkle an even amount of goat cheese over the apples. Place a few spoonfuls of caramelized onions over the cheese.
Place the pizzas on parchment paper in the oven and bake for 15-20 minutes, until the goat cheese is melted and the apples are soft. Be careful not to over-bake, as this will make the flatbread too crunchy.
Once the pizzas are out of the oven, top immediately with the caramelized walnuts, spinach or arugula, and a drizzle of honey. Enjoy right away!
Notes
If using dough instead of flatbread, the baking temperature should be adjusted to 450 and the cook time should be reduced.