No, you can't, certainly not in this particular sentence, with the verb "a mânca"
= "to eat," which is more about when you are going to eat the honey, as part of which course of the meal.
You might be able to say "Eu cumpăr miere pentru desert." = "I buy honey for the dessert." (i.e., as an ingredient for a dessert I'm going to prepare or as something I'm going to eat on its own for dessert, although the latter might work better with fruit or cakes.)