Have you thought about writing me "back"?
Pensaste alguna vez en escribirme "?" I wonder. Gracias.
3 Answers
"responder a mis cartas", "corresponderme", "escribirme de vuelta"
I need pensar to be involved la carta to be understood.
Your "requirements" seem somewhat odd. In the first place, Gekko-kun's suggestions referred to the second part (not the entirety) of your sentence. More importantly, you seem to suggest that you will not be satisfied with any response that does not involve specific words (the most obvious translations of specific words in English).
In some circumstances, a translation can closely mirror the syntax of the original and still be a reasonable utterance. However, in many cases, there exists a phrase that almost any native-speaker would use in the same situation that does not correspond (syntactically) to the English.
In the latter situation, you are faced with a choice: Will you insist on a translation that reflects the English construction or will you settle for what Spanish speakers would be likely to say?
I need pensar to be involved la carta to be understood. ¿Pensanste en responderme?