Line a small sheet pan with parchment and clear space in your freezer.
Soften the ice cream at room temperature until scoopable, about 5–10 minutes.
Melt chocolate chips with coconut oil in the microwave in 20–30 second bursts, stirring until smooth.
Spread a thin layer of melted chocolate on half of the graham squares and place them on the pan to set.
Swipe the remaining graham squares with marshmallow creme; sprinkle lightly with flaky salt if using.
Scoop ice cream onto each chocolate-coated cracker, about 1/3–1/2 cup per sandwich.
Cap with a marshmallow-coated cracker and press gently to level the ice cream.
Smooth the sides and roll edges in mini chocolate chips if desired. Freeze until firm, at least 2 hours.