Line an 8×8-inch pan with parchment paper, leaving overhang.

Melt chocolate chips, condensed milk, and butter over low heat, stirring constantly until smooth.

Remove from heat and stir in vanilla extract and salt.

Let mixture cool 2–3 minutes, then gently fold in marshmallows and chopped cherries.

Spread evenly into prepared pan and add optional toppings if desired.

Refrigerate until fully set, then lift out and slice into bars or squares.