Beat together the Lotus Biscoff spread (160g) and butter (80g) until fully combined and soft. Either use an electric mixer on a low speed or beat by hand.
Add the icing sugar (120g, a tablespoon at a time). Beat in each addition of icing sugar until fully combined.
Check the consistency of your buttercream, it should be soft but not runny. If it is a little too stiff then add little milk (no more than one teaspoon at a time). Fully beat in each addition then recheck the consistency before adding more.
