A person who makes biscuits can be referred to as a baker. In a more specific context, if they specialize in making biscuits, they might be called a biscuit maker. However, the term "baker" generally encompasses anyone who bakes various types of goods, including biscuits.
A person that makes candles is called a chandler.
Age of the biscuits, that expired and heat if left in the car too long.
In Ireland and England alike, cookies are chocolate-chipped circular biscuits. If you're American, I think you call all biscuits cookies. If so, the answer you are looking for is biscuits.
the person who makes spelling mistakes is called cacographer.
The person that makes and sells sweets is called a confectioner.
There is no specific collective noun, but they would normally be known as a packet of biscuits or tin of biscuits.
A person who makes saddles would be called a Saddler.
During the Civil War, dried biscuits were called hardtack.
A person who makes things out of stone is called a stonemason or a stone carver.
Biscuits.
They were originally called Rolled Oats Biscuits. Subsequently they were renamed Anzac Crispies - and later Anzac biscuits.
A person who makes mirrors is called a mirror maker or a glassworker specialized in mirror production.