Recommend trying this.

Very knowledgeable and friendly staff who will talk you through everything, providing guidance and advice. Follow it to the letter and you’ll avoid any surprises.
Depending on what you choose, you should expect to pay between €15 and €25 for around 10g (at the time of writing) and I fully encourage you to buy some dark chocolate too. The higher percentage chocolate has less of an effect on your experience but does make the truffles more palatable.
We chose to walk in the park before visiting an art gallery and we are all agreed it was among the best experiences of our lives. Highly recommended.