Why Your Cakes Sink - And How to Prevent It

Baking a cake feels a little bit like magic - mix a few ingredients, pop them in the oven, and wait as the sweet aroma fills the kitchen. But nothing ruins that joy faster than opening your oven to find a sunken cake, caved in like a tiny culinary crater.

Don't worry: you're far from alone. Even experienced bakers face this occasionally, and the reasons behind it are surprisingly scientific. 

Grab a cup of tea, and let’s break it down.

1. Your Cake Is Underbaked

This is the number-one reason cakes sink. Baking sets the structure of your cake. If the center hasn’t fully set, it collapses as it cools.

Why It Happens

• Oven temperature was too low

• You opened the oven door too early

• The batter was too wet

• You removed the cake before it was done

How to Prevent It

✔ Use an oven thermometer. Many ovens run 10-25°F off.
✔ Don’t open the oven door during the first 20-30 minutes.
✔ Test doneness the right way:
- The center should spring back when touched
- A toothpick should come out with just a few moist crumbs
- The cake should pull slightly away from the sides

2. Too Much Leavening (Baking Powder or Baking Soda)

You’d think that more leavening would mean a fluffier cake - but it actually does the opposite.

Why It Happens

Too much baking powder or soda causes the cake to rise fast, then collapse because the structure cannot support the height.

How to Prevent It

✔ Measure carefully - level off teaspoons with a straight edge
✔ Follow the recipe exactly
✔ Check expiration dates: old baking powder = weak rise, fresh = strong (and maybe too strong if you overdo it!)

3. Old or Weak Leavening

The opposite problem can also cause sinking.

Why It Happens

Expired baking powder/soda doesn’t generate enough gas, making the structure unstable.

How to Prevent It

✔ Replace baking powder every 6 months
✔ Test baking powder:
Mix ½ teaspoon in hot water - if it bubbles vigorously, it’s good

4. Overmixing the Batter

It’s a common mistake: you mix enthusiastically, expecting a smooth batter. But too much mixing leads to too much gluten - a dense cake that falls in the center.

Why It Happens

Overmixing overdevelops gluten, trapping gases unevenly and weakening the cake’s structure.

How to Prevent It

✔ Mix until ingredients are just combined
✔ Use the lowest speed on electric mixers
✔ Fold gently with a spatula when adding dry ingredients

5. Incorrect Oven Temperature

Temperature is everything in cake baking.

Why It Happens

• Oven too hot → cake rises rapidly, then collapses

• Oven too cool → cake never fully sets

How to Prevent It

✔ Use an oven thermometer
✔ Preheat fully before baking
✔ Avoid baking multiple items at once if your oven has uneven heat

6. Opening the Oven Door Too Early

We’ve all done it. You smell sweetness and can’t resist peeking.

Why It Happens

Heat escapes, interrupting the rise. The delicate structure deflates instantly.

How to Prevent It

✔ Don’t open the door until at least 75% of the baking time has passed
✔ Use your oven light for checking progress

7. Incorrect Pan Size

Yes - your pan might be sabotaging your cake.

Why It Happens

• Too small → batter rises rapidly and collapses

• Too large → batter bakes thin and dries prematurely

• Too deep → center stays underbaked

How to Prevent It

✔ Always use the pan size the recipe recommends
✔ If you must substitute, adjust baking time accordingly
✔ Fill pans only ½ to ⅔ full

8. Too Much Liquid or Too Little Flour

The balance of wet and dry ingredients is key to structural stability.

Why It Happens

A batter that is too wet never fully sets. A batter that is too dry crumbles and collapses.

How to Prevent It

✔ Weigh ingredients with a kitchen scale
✔ Avoid substituting ingredients unless you know how they behave
✔ Make sure eggs are large (not medium or jumbo), unless otherwise stated

9. Creaming Butter and Sugar Incorrectly

This step builds the air structure that your cake relies on.

Why It Happens

• Over-creaming → too much air → collapse

• Under-creaming → too few air pockets → dense, sunken center

How to Prevent It

✔ Beat butter and sugar for 2-4 minutes
✔ The mixture should look pale and fluffy
✔ Butter must be softened - not melted, not cold

10. The Cake Cooled Too Fast

Even after baking, the structure is fragile.

Why It Happens

Moving the cake from hot oven air to cool countertop air can cause collapse.

How to Prevent It

✔ Cool cakes gradually: open the oven door slightly for 5 minutes before removing
✔ Place the pan on a cooling rack away from drafts

Bonus: How to Fix a Sunken Cake

Okay - let’s say your cake sunk. Don’t toss it! Here are some clever saves:

✔ Turn it into a layered cake

Cut the top off, level it, fill with cream or fruit, and stack.

✔ Make a trifle

Cube it, layer with pudding, whipped cream, and berries.

✔ Fill the dip with frosting

Your secret is safe with us.

✔ Transform it into cake pops

Crumble, mix with frosting, dip in chocolate - perfection.

A sunken cake isn't the end of the world - it’s just a chance to learn. Baking is both an art and a science, and once you understand the “why” behind common cake mishaps, you’ll start turning out perfect, level cakes every single time.

So next time your batter goes into the oven, you’ll know exactly what to look out for - and how to prevent that frustrating collapse.