For winter school grades 3, 4 and 5, I filled 80 minutes with cookies. I took that cookies ppt and modified it, removed the game part. Showed them examples of cookies, asked a few questions, blah blah blah, then went over the cookie recipe. Grades 3&4 we did the gap-fill together. Grade 5 did it by themselves then we checked the answers. Then they had word searches. (I copied the recipe and the word searches back to back.) After the break, we made the cookies (I brought in my toaster oven). While the cookies baked (about 10 minutes), the younger kids played jenga while I cleaned up, and the older kids cleaned up for me (and learned how horrible it is to clean up peanut butter with ice cold tap water). That took up the majority of the 80 minutes.
Easy recipe. Peanut butter + sugar + egg.
To use less peanut butter, and to accommodate for a small class, I cut the recipe in half, which is why it says to measure out half the egg. Was perfect amount for 8 kids.