Line an 8-inch pan with parchment, leaving overhang. Lightly grease the paper.
Melt butter in a large pot over medium heat until foamy.
Stir in cookie butter until smooth and combined with the butter.
Add salt and vanilla. Tip in marshmallows and stir until fully melted and glossy.
Remove from heat. Fold in crispy rice cereal until evenly coated.
Gently mix in chopped spiced cookies, keeping some chunks intact.
Press mixture into the pan with a greased spatula. Don’t pack too firmly.
Drizzle warmed cookie butter over the top and swirl. Cool, then cut into squares.