Line a 9x9” baking pan with parchment paper on both sides, so that it hangs off the sides.
Line the bottom of the pan with 15 of the speculoos cookies, with the decorative side facing down. Typically, 2 rows of 6 biscuits, followed by a row of 3 biscuits laid out lengthwise.
Place the softened ice cream in a large bowl. Heat the cookie butter in the microwave in 20 second increments until runny and smooth. Pour the cookie butter into the ice cream, and swirl to gently incorporate, leaving a few ribbons of cookie butter rippled throughout.
Pour the ice cream over the cookies, and spread to evenly cover the pan. Then top with the remaining cookies in the same orientation as the bottom cookies, this time with the decorative side facing up.
Freeze for 6 hours or overnight.
Using the cookies as a guide, cut into ice cream sandwiches, and serve.
