Step 1Make dough: In a large bowl, whisk flour with salt. On the large holes of a box grater, grate frozen butter into bowl and stir just until coated with flour. Stir ½ cup ice water into dough until just combined. Add another tablespoon water, if necessary.

Step 2Scrape dough out onto a work surface. Knead just to bring the dough together into a ball. Divide into two pieces and wrap each in plastic and flatten each into a disc. Refrigerate until cold, at least 1 hour.

Step 3Make filling: In a large bowl, whisk together pumpkin, condensed milk, yolk, brown sugar, and pumpkin pie spice until smooth.

Step 4Make mummies: In a small bowl, combine sanding sugar and cinnamon. Roll each disc of dough into 9"-x-10" rectangles. Cut one rectangle into 1/4" thick strips. Cut remaining rectangles into twelve 3"-x-2" pieces.

Step 5Line a baking sheet with parchment. Spread pumpkin filling onto the 12 rectangles and evenly space rectangles on prepared baking sheet. Crisscross strips over filling on rectangles to create mummy wrapping, trimming as necessary and leaving room for eyes. Brush exposed parts of dough with egg wash and sprinkle with cinnamon sugar. Transfer mummies to freezer, 20 minutes.

Step 6Preheat oven to 400°. Bake until top is golden, about 20 to 22 minutes. Let cool.

Step 7Dip bottom of candy eyes in caramel and adhere two eyes onto the filling of each mummy.