Doubling a Recipe....Rely on Instant Read Thermometer?

[gulfporter]

I have made cranberry squares for over 20 years; last year I doubled it for the first time.  I baked it 50% longer (from 1 hr to 90 minutes).  By then the outer crust was getting too dark.  I did what I can best describe as an inconclusive toothpick test.  After it cooled, I discovered the center was severely underbaked.

 

This 'cake' has no leavening, eggs, a ton of melted butter with plenty of nuts and fresh cranberries.  It calls for an 9 inch square pan.  It has always been fully baked at the 1 hour mark.  I haven't even toothpick tested it for the last 15 years....it has always been fine.  

 

If I try to double it again this year, I am thinking of using my thermapen rather than the toothpick test.  Google indicates a cake should have an internal temperature between 185 and 200.  Should I aim for the lower or higher end for this sort of bake?  

 

Or should I just go buy another 9 inch square pan and forget about doubling it in one oblong pan (9 x 13  is what I used last year).  

 

 

[Darienne]

Being far down on the scale of 'expert' when it comes to this sort of question...as I read your post I immediately settled on the second pan solution.  

[blue_dolphin]

A 9 x 13 inch pan is a little less than 1.5 x as large as a 9 x 9 inch, not twice as big.

Either multiply your recipe quantities by 1.5 x (or 1.44 to be precise 🙃) for the 9 x 13 or use 2 pans.

[JeanneCake]

well, first I'd bake it in the 9" pan and use the thermapen to see what it registers since you know it is fully baked in that timeframe in that pan. I'd probably buy a second pan to be honest; there are so many variables to consider when you  are doubling the recipe.  And just to make it easier, weigh the final batter amount so you can still double the recipe when you prep it but scale it correctly into two different pans.

 

 

[keychris]

As much as I like using my thermometer for bread, I do cakes by feel.

[gulfporter]

Thx for the advice.  A new pan is on its way via Amazon.com.mx