20 Most Recent Siemens H 4680 BP KAT Stainless Steel Electric Single Oven - Page 3 Questions & Answers

The glass is replaceable. You need to get the exact glass replacement kit from the manufacturer. I had to have mine replaced about a year ago due to condensation between the 2 glass panels and was able to get the replacement for $0.00.
Suggest to Siemens that the glass on yours should not have shattered and therefore was probably defective and you may luck out and get the glass for free. It's worth a try.

Try replacing the temperature probe that sticks into the oven, that is the likely cause.