In a small saucepan over low heat, combine the cookie butter and sweetened condensed milk. Stir constantly until melted and smooth — about 3 minutes.
Add the whole milk, maple syrup, cinnamon, and salt. Continue stirring until the mixture is fully combined and glossy — about 2 to 3 minutes.
Remove from heat and let cool at room temperature. The sauce will thicken as it cools.
Pour into a jar or squeeze bottle for easy drizzling.
Store in the refrigerator for up to 2 weeks. Reheat in the microwave for 10–15 seconds or until pourable before using.