As it turns out, we never used to microwave over the past two years and used our mini toaster oven a ton, so I swapped the microwave for a bigger oven. Now we do fresh cornbread, cupcakes, cookies, etc. anytime we want.
In order to make it safe did a few things to keep it cool. First I lined the cabinet with foil insulation:
On the back wall, you can see a small thermostat controller that I bought off eBay for about $8.00 shipped. I have it set for 110 degrees Fahrenheit. When the toaster reaches that level, it turns on a 4 inch fan to draw cool air in from the bottom and push it out the top vent.
I ran tests baking for 60 minutes at its max temp of 450 degrees and I never had the internal temp go higher than 130 and the ceiling temp above the vent higher than 95.
The last think I did was fab a trim ring out of 1/4 MDF and paint it with Rustoleum Heirloom White spray paint to match. I attached the trim ring using cabinet door clasps which you can see on each side of the opening:
This mod may not be for everyone, but it works for us!