Once again I found the instructions on the box to yield a less than ideal result. When followed I found the cupcakes had an insufficient vanilla flavor. I also found that you needed truly melted shortening to get the texture right. These contain eggs. I have done an egg-free version, but I am not happy with it yet.
Again, this is adapted from the recipe on the box.

Ingredients
1 box Betty Crocker Gluten Free Yellow Cake Mix
2/3 cup Good Karma Flax Milk
3 large eggs
4 tsp gluten-free vanilla
1/2 cup Spectrum Organic Butter Flavor Shortening

Equipment
1 microwave safe container for melting shortening (ideally this will be a pyrex measuring cup)
Measuring cups and spoons
1 electric mixer
1 12 well standard cupcake pan
12 cupcake liners
1 spatula
1 gravy ladle for measuring out cupcake batter

Instructions
Melt shortening in microwave safe measuring cup. Allow to cool to a temperature that you can comfortably touch, so hot but not burning hot.
Put shortening in bowl of electric mixer, turn mixer on low
Add eggs to shortening and mix to combine and create an emulsion
Add vanilla and flax milk
Add cake mix. Mix on low for 30 seconds
Mix on medium for a full 4 additional minutes. Do not undermix. At the end it will start to look like cake batter.
Preheat oven to the temperature recommended on the box (325 for dark or nonstick pans and 350 for shiny aluminum)
Put in 12 paper cupcake wrappers
Divide evenly between 12 cupcakes. They will appear very full
Bake for about 20 minutes or until a toothpick stuck in the middle comes out clean
Cool and frost.