The very first recipe I "let" my students cook is Homemade Oreos. I have made (and loved) these cookies since my childhood. They make a great first lab as they are easy and delicious. My class periods were 47 minutes and there are some groups that struggle getting them done on time- but it is possible. Because they are easy, they are a good way for groups to learn how to work together- since it is their first time in the kitchen together. Whenever cakemixes and icings are on sale I try to stock up so it can be an inexpensive lab as well. You can use any cake mix you desire- chocolate is the best with cream cheese icing. Mmmmm. I always demo this lab (since it is their first) and have a LOT of cookies leftover. You can be "mean" (their words, not mine) and not allow them to taste them the day of your demo- or you could give them halfsies and should have enough for both purposes. Unless you have longer class periods than I did, you likely won't have time for a demo and this activity... but you can try. These cookies are also great in the freezer if you want to freeze them after your demo and do this activity at a later date.
I like to tell my students that Oreo heard of my homemade version so they came out with Cakesters to compete. :) So to show the Oreo makers I like a little friendly competition, I came up with this activity to compare the two. This is the front of the worksheet. I figured out how much each of the ingredients in the homemade oreos cost- cake mix, oil, eggs and icing. We do the math as a class to figure out the total cost, the total number of cookies made and finally the cost for one cookie. This is a little challenging as you have to get the cookies to be the exact same size as the cakester. I have yet to accomplish that so when I do, I will give you the correct numbers. We then figure out the cost for one cakester.
Then comes the discussion on which is the better buy. It SHOULD be the homemade by almost half.
I then give them a few minutes to think of some reasons why you would purchase food instead of make it at home AND why you would make something at home rather than buy it from the store. Then the fun REALLY begins with more math on the back. I cut the nutrition labels from each product and pasted them on the worksheet. Using the amounts on the front and the serving sizes, they need to figure out the fat grams and calories for each ingredients. This can be a little tricky since the fat grams/ calories for the ENTIRE cakemix are needed but the serving size is only 1/12. So they need to multiply the calories for one serving by 12. Likewise for the fat grams. The oil serving size is 1 Tablespoon but you use 1/2 cup in the recipe. This is a good review of equivalents.
Once that is all figured out, you need to add it up for the entire batch of cookies, then divide by the number of cookies made to figure out the information for one homemade Oreo.
The Cakester math is much easier as you just need to divide by 2.
If the cookies are the same size, the homemade oreos should be a little "healthier".
I try to do this as a class since some parts can be challenging. There are a few that give up or drift off so I give a tasty reward at the end to those who turn in a completed and correct worksheet- half a Cakester and half a Homemade Oreo. This of course tends to motivate those that gave up or drifted off.
You can do this activity with anything that you can buy at the store and make homemade. And if you choose something that has even more "versions" you can add more math to the mix- such as pizza- homemade, restaurant, frozen, deli, etc.
The possibilities are endless.