Preparation

Make the dough

• Combine the flour, turmeric, and 1/2 tsp. each salt and pepper in a food processor; pulse to combine. Add the butter and pulse until the mixture resembles coarse meal. Add the egg, if using, and pulse for no more than 10 seconds to incorporate. Slowly add the water, 1 Tbs. at a time, while pulsing until the dough comes together and forms a ball. Wrap in plastic wrap, and refrigerate for at least 30 minutes and up to 2 days.

Make the filling

• In a medium bowl, combine the cheese, mayonnaise, garlic and onion powders, and jalapeño, if using. Stir well to combine. (You can make the cheese filling up to 1 day ahead. Store in an airtight container in the refrigerator.)
• Arrange the tomato slices on two layers of paper towels, sprinkle with 1/4 tsp. salt and 1/4 tsp. pepper, and let drain for at least 20 minutes.

Bake the hot brown bites

• Position a rack in the center of the oven, and heat the oven to 350°F. Generously coat a 12-cup muffin tin with the cooking spray.
• Bring the dough to room temperature. Lightly flour a work surface. Roll the dough into a 12×14-inch rectangle. Using a 31/2-inch round cutter or a pint glass, cut 12 circles from the dough, folding and rerolling the scraps as necessary. Nestle the dough circles into the prepared pan, allowing the dough to come three-fourths of the way up the sides of the cups. Prick the dough with a fork.
• Divide the ham, turkey, and cheese mixture among the muffin cups, pressing down lightly after each addition. Top each with a tomato slice and a small sprinkle of bacon bits. Bake until browned and bubbling, 20 to 25 minutes. Cool for 15 minutes before removing from the pan. Serve sprinkled with the parsley, if using.