Baked Spaghetti Squash Fritters

Preheat oven to 400 degrees F. Arrange squash halves, cut-sides down, on a large rimmed baking sheet lined with parchment paper. Bake until very tender when pierced with a fork, about 50 minutes. Remove from oven; let cool slightly, about 10 minutes. (Alternatively, place squash halves, cut-sides down, in a microwavable baking dish. Pierce the squash shells with a fork. Add 1/2 to 3/4 inch of water to the dish. Cover and microwave on High until the squash is tender when pierced with a fork, 10 to 15 minutes.)

Using a fork, scrape out the squash flesh (spaghetti-like strands) to equal 3 packed cups. (Reserve any remaining squash for another use.)

Line a rimmed baking sheet with parchment paper; brush with 1 tablespoon oil and set aside. Working in batches, place the squash strands and onion in the center of a clean towel; squeeze firmly over the sink to remove as much liquid as possible. Combine the squeezed squash mixture, egg yolk, baking powder, pepper, salt and 1/2 cup scallions in a large bowl. Whisk egg white in a small bowl until frothy; stir into the squash mixture.

Scoop about 3 tablespoonfuls of the squash mixture into a mound on the prepared baking sheet; flatten into a 3-inch round using a spatula. Repeat the process with the remaining squash mixture, making 8 fritters total spaced 2 inches apart.

Brush the tops of the fritters evenly with the remaining 1 tablespoon oil. Bake until crisp and golden, 10 to 12 minutes per side. Remove from the oven. Sprinkle the fritters evenly with cheese. Continue baking until the cheese melts, about 2 minutes. Top the fritters evenly with sour cream, crumbled bacon and the remaining 1/4 cup scallions.