Make the empanada dough
In the bowl of a food processor, pulse flour with salt a few times to mix.
Add butter to flour mixture, pulsing 15 – 20 times until dough begins to look like coarse crumbs and butter is broken up into pea-sized pieces. *see note
Whisk egg, egg yolk, ice water and vinegar together in a small bowl, then add to flour and butter mixture.
Pulse to start incorporating liquids, then run machine for 15 – 30 seconds until a shaggy dough forms.
On a floured surface, dump dough out of bowl and gather together. Use the heel of your hand to lightly knead dough a few times. (If it is too dry and crumbly, add 1 tbsp. ice water and work into dough.)
Knead dough a few times on the counter until it comes together and looks smooth.
Divide dough in half, press each half into a rectangle and wrap tightly with plastic wrap. Refrigerate 30 minutes to 1 hour.
Roll each half out to roughly 1/8” thickness (between sheets of parchment is helpful!).
Cut circles out with 3 1/2 - 4" round cutter to make disks. Cover with plastic wrap and store in refrigerator until ready to fill.
Make pumpkin and chorizo filling
Heat a medium skillet over medium high heat. Add chorizo, breaking it up as it cooks. (If you have a lot of fat, drain the chorizo before proceeding to the next step)
Add onion and garlic to chorizo and cook until softened, about 6 – 8 minutes.
Season with salt and pepper. Remove from heat.
Fold in roasted calabaza (pumpkin/squash) and crumbled cheese.
Set aside to cool before filling empanadas.
Assemble and bake empanadas
Preheat oven to 375°F / 190°C / Gas mark 5
Remove dough discs from refrigerator and allow them to sit on the counter, covered, as you get ready to assemble empanadas.
Place 1 1/2 tablespoons of filling in the center of the empanada.
Fold in half, pressing filling down, then pinch closed with your fingers. Use a fork to crimp the edges together.
Brush with egg wash (if desired), then place on parchment paper-lined baking sheet.
Bake for 18 - 25 minutes, or until golden brown.