01 -
Set oven temperature to 350°F (175°C) and allow it to reach temperature.
02 -
Line a casserole dish with parchment paper or lightly coat with cooking spray.
03 -
Spread a thin layer of mustard onto one side of each Ritz cracker.
04 -
Top each prepared cracker with a slice of deli meat and a slice of cheese.
05 -
Place a second Ritz cracker on top of each to form mini sandwiches, pressing gently to secure.
06 -
Arrange all sandwiches in a single layer inside the prepared casserole dish.
07 -
Brush the tops of each sandwich with the melted unsalted butter.
08 -
Bake on the center rack for 10–12 minutes, or until cheese melts and sandwiches are warmed through.
09 -
Serve warm as an appetizer or alongside chosen accompaniments.