Strawberry cupcakes with sunken middles. Help!

Another high elevation possible solution: refrigerate your batter for a couple of hours before baking. I live at 6000 feet, and it has helped all my cakes, cup or otherwise.

Is there a way you can determine, weight-wise (or even volumetrically), what amount of pureed strawberries is sufficient? Measuring fruit volumetrically, ahead of time and expecting the puree to be consistent is tricky. I looked at the recipe, and I can't imagine a scant teaspoon of baking powder is too much leavening. Since there is acidic ingredients in the cake, have you tried adding a touch of soda to neutralize that?

Problems may be coming from bakers who live at elevations above 2000'. You are at sea level, which (mysteriously) all recipes presume. If you don't mind forwarding problems to me, I would be glad to send them adjustments to leavening - which needs to be decreased - and protein - which need to be increased, relative to every 500' of elevation beginning at 2000'.

I saw the cupcakes on your site and they are wonderful looking. There are several factors that can cause a cake to sink in the middle, wrong size pan (which in this case probably wouldn't be since they are cupcakes) or oven that is not consistent with the temperature, it could also be the leavening agent, sometimes too much baking powder or baking soda can cause this. It is also difficult when adding fruit to a cake batter because fruit or berries can vary in juiciness, sweetness etc.. it could very well be that it's the fruit thats the culprit. I looked at the cake you adapted your recipe from and it's stunning. If you consistently have comments from people that their cakes are sinking in the middle it's hard to ascertain if it's something they are doing or their oven. When I looked at your recipe my first thought is that 1 cup of flour is not enough, there is a lot of liquid, strawberry and coconut milk and then 8 tbs butter. I am not an expert but I think there needs to be more flour and also a slight increase on the leavening agent. Sorry to ramble.

*levening