Preheat oven to 375°F and line two baking sheets with parchment paper.

In a large bowl, combine flour and salt. Cut in cold butter using a pastry cutter or fork until mixture resembles coarse crumbs.

Gradually add cold water, stirring until dough comes together. Form into a ball, wrap in plastic, and refrigerate for 15 minutes.

While dough chills, heat olive oil in a large skillet over medium heat. Add diced onions and cook until softened, about 5 minutes.

Add minced garlic and finely chopped Scotch bonnet pepper, cooking for 1 minute until fragrant.

Add chopped spinach (or callaloo) to the skillet and cook until wilted, about 4-5 minutes. Season with salt, black pepper, thyme, and a pinch of cayenne.

Remove skillet from heat and gently fold in the crabmeat. Taste and adjust seasonings. Allow filling to cool completely.

Remove dough from refrigerator and divide into 16 equal portions. Roll each portion into a circle about 5 inches in diameter on a floured surface.

Place 2 tablespoons of filling in the center of each dough circle. Fold dough over to create a half-moon shape and crimp edges with a fork to seal.

Place empanadas on prepared baking sheets. Beat egg with 1 tablespoon water and brush over empanadas.

Bake for 22-25 minutes until golden brown and crispy. Let cool for 5 minutes before serving.