A brownie pan with two food safe thermocouples, one in the brownie batter and one in the air next to the pan, is put in a pre-heated oven, and the temperature profiles recorded and displayed.
Clean copper wire is used to make an armature for the thermcouple wires. Crimp the center of a 20 cm piece of 14 ga wire on the side of the baking pan. Bend loops at the ends of the copper wire to hold the thermocouple wire.
The oven temperature thermocouple should be about five centimeters away from the pan, at the same level as the center of the pan. The brownie thermocouple is immersed in the brownie batter with the bead at the center, and the lead in wire at a shallow angle in the batter to avoid piping heat into the center along the thermocouple wire.
Thermocouples from Omega Engineering, and data acquisition hardware and software from Vernier Instruments.