The secret to making these cookies taste their best is to use high quality butter and pure vanilla extract. Butter in the States is graded according to flavor, color, texture, aroma and body and one easy way to tell the quality of the butter is by the letter code or numerical number listed on the butter’s package. The highest grade is AA (93 score), then A (92 score), followed by B (90 score). In choosing vanilla extract, the first thing to do is to make sure that it is labeled “pure”. There are quality brands to be found in your local grocery store. Just stay away from the ones labeled “imitation” vanilla extracts as they are made with synthetic vanilla (from glycoside found in the sapwood of certain conifers or from coal extracts) and leave a bitter aftertaste.