Line a 9x13-inch pan with parchment. Lightly grease the paper with the oil.
Melt the butter in a large pot over low heat.
Stir in the cookie butter and marshmallows. Cook gently, stirring, until smooth and glossy.
Remove from heat. Mix in the vanilla and salt.
Fold in the cereal and crushed cookies until evenly coated. Work quickly.
Press the mixture into the pan with a buttered spatula. Do not pack too firmly.
Drizzle with melted white chocolate and warmed cookie butter. Swirl, cool until set, then cut into squares.
Notes
Try browning the butter for a nutty twist, or swap the white chocolate drizzle for semi-sweet. For extra texture, sprinkle flaky sea salt on top. Store airtight at room temperature for up to 3 days, or wrap and freeze for 1 month.This recipe is an original creation inspired by classic Biscoff Rice Krispie Treats Recipe flavors. All ingredient ratios and instructions are independently developed.