Fat content vs baking time?

This year’s Christmas dessert was the same as last year’s dessert. Same recipe, also. Mixed everything together, put it all in the bundt pan in a water bath, covered with foil, and popped into the 350 oven (verified by oven thermometer). After the one hour baking time (which was plenty last year), I checked for doneness, and to my surprise the pick came out covered with what looked like chocolate pudding. It took another half hour to get an acceptable bake.

Now, the only thing that changed from last year to this year was that I used Irish butter instead of our usual local butter, and that we have had a huge amount of rain this December.

To my knowledge, fat content doesn’t increase baking time. Am I incorrect?

I doubt that the difference in fat content between two types of butter would make any difference in baking time. It’s more likely that you made a mistake in measurement of some ingredient, or that some other ingredient was different (e.g. jumbo vs. large eggs). Another possibility is that the water bath was deeper this year.

That’s a weird one.

I wouldn’t expect the fat content between two butters to effect the baking time at all. I pretty much exclusively bake with high-fat butter, and I’ve never had to adjust baking times.

Is it possible that the batter was colder than last year? What about the bundt pan - same pan, or was it thinner/thicker/taller/any different than the one you used last year?

Same pan, eggs were room temp, so was the butter. The water bath was likely deeper, as I actually measured it this year. There appeared to be a lot of moisture on top of the cake when I lifted the foil, so perhaps that was the problem. I removed it completely for the last bit of baking.