How to cream when there is more sugar than butter in the recipe?
For the purpose of mixing butter and sugar (oddly enough) are considered "wet" ingredients. What other wet ingredients are in your recipe? Eggs, Milk, Extract... these may be added in the creaming process to get a more smooth "paste" rather than a crumble.

You may also wish to try starting with 50g (or even less) of sugar to get the "smooth mass" (paste) that you are accustomed to and then slowly add the remaining sugar.