is a baking cake that burns a chemical or physical reaction?

Answer 1

Baking a cake is several chemical changes.
The baking powder combines with acid(which is found in the baking powder mixture) and gives off bubbles of CO2 to make the cake raise.
The eggs are cooked, denatured protein.
The wheat flour protein is also denatured by heat,
The browning on the surface is a chemical combination of sugars and proteins.
When it burns, that is another chemical change, an oxidation of the materials.

The evaporation of liquids in the process would be physical.

Answer 2

I agree
Chemical

cake + Heat ---> burnt cake + CO2
endothermic reaction forming burnt cake and CO2(smoke)

Answer 3

Definitely a chemical change, because a new chemical (carbon) has been formed.