This is a step up from the kindergarten/beginners writing prompt. Students are expected to use sound to letter correspondence, capital letters at the beginning of a sentence, finger spaces, and end stop (periods) to write about their favorite story.
You can have the students draw a picture first or write their sentences first. I usually ask the students to write at least 2-3 sentences explaining why they have chosen a particular story. What was your favorite part of the book? Which character was your favorite? Make sure you model through a mini-lesson before you have the students write on their own! ENJOY :)