In a large bowl, combine bread crumbs and buttermilk, stirring until combined. Let stand for 5 minutes. Add eggs, Dijon, Worcestershire, Italian seasoning, onion, garlic, salt, and pepper, stirring until combined. Add bison to bread crumb mixture, using your hands to mix until well combined.
Place 2 (24-inch) pieces plastic wrap onto countertop, slightly overlapping. Place bacon slices on plastic wrap, overlapping slices to form a 10x8-inch rectangle. Divide meat mixture in half. Place 1 portion over bacon, patting to form a 4½x8-inch rectangle. Spread Spinach-Mushroom Filling over meat mixture, leaving a 1-inch border. Top filling with remaining meat mixture, pressing edges to seal. Using plastic wrap, turn meat mixture, wrapping with bacon and pressing to form a 10x6-inch loaf. Wrap plastic wrap around meat loaf securely to hold shape. Transfer to a baking sheet and refrigerate for at least 20 minutes.
Preheat oven to 425°.
Remove plastic wrap, and place meat loaf in a 12-inch square cast-iron skillet, bacon side up. Let rest for about 10 minutes.
Bake until a meat thermometer inserted in center registers 145°, 40 minutes. Brush top of meat loaf generously with Chili Glaze. Bake until a meat thermometer inserted in thickest portion registers 160°, about 10 minutes more. Let rest for 10 minutes before serving. Serve with remaining Chili Glaze. Garnish with parsley, if desired.
Recipe by Southern Cast Iron at https://southerncastiron.com/bacon-wrapped-stuffed-bison-meat-loaf/