Baking a cake today isn’t quite the same as it was decades ago. If you’ve ever followed a vintage recipe or tried to recreate an old family favorite using a boxed cake mix, you might have noticed something doesn’t turn out quite right. That’s because modern cake mixes are smaller than they used to be, leading to shorter, denser cakes that might not match the fluffy, full-sized desserts of the past. But don’t worry—there’s a simple way to adjust your cake mix to bring it back up to the original size.
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Cake Mix Upsizer
Why Are Cake Mixes Smaller Today?
Years ago, standard boxed cake mixes were 18.25 ounces, but today, most are only 15.25 ounces. This change happened gradually as manufacturers adjusted packaging and formulations, often without much notice to home bakers. The difference of just a few ounces might not seem like a big deal, but it can affect the texture, volume, and overall structure of your cake, especially if you’re using a recipe that was designed for the larger mix size.
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Baking with the Adjusted Mix
Once you’ve added the extra dry mix, prepare your cake as usual, following the instructions on the box. Your cake should now bake up just as it would have decades ago—full, fluffy, and perfectly suited for vintage recipes.
Many vintage recipes rely on an 18.25-ounce cake mix as a base, whether for cakes, cookies, or even bars. When using a modern 15.25-ounce mix, you may end up with a noticeably smaller cake, or worse, the ratios of ingredients might be off, affecting moisture and structure. If your cake seems less fluffy or doesn’t bake up as high as expected, the smaller mix size could be the culprit.
Ever wonder what “slow oven” or “moderate oven” really means? Find out how these vintage terms translate to modern temps and bake those classics just right! View our article on Decoding Vintage Oven Temperatures.
How to Upsize a Cake Mix to 18.25 Ounces
Fortunately, you don’t have to abandon your favorite vintage recipes. Adding a simple homemade dry mix can easily increase the size of a modern 15.25-ounce cake mix to the original 18.25-ounce.
The recipes below are extra, so save them for later, or cut the measurements in half if you don’t want to store them for later.
Here’s how to do it:
Cake Mix Upsizer
If you've ever baked a cake from an old recipe and wondered why it didn’t turn out quite right, the downsized cake mixes of today might be to blame.
Ingredients
For Chocolate Cake Mixes:
- 1/2 cup and 1 tablespoons all-purpose flour
- 1/2 cup sugar
- 2 tablespoons cocoa powder
- 1 teaspoons baking powder
- 1/8 teaspoon baking soda
For White and Yellow Cake Mixes:
- 3/4 cups all-purpose flour
- 1/2 cup sugar
- 1 teaspoons baking powder
- 1/8 teaspoon baking soda
Instructions
- Whisk all dry ingredients together and store them in a mason jar or airtight container.
- When adjusting a 15.25-ounce cake mix to the original 18.25-ounce size, add 6 tablespoons of this dry mix to your boxed cake mix before preparing the batter.
- Store the remaining mix in a tightly sealed container in the pantry.