Diagnosis
A complete failure of the bake function points to a dead bake igniter or a failed oven control board. The bake igniter is the first check.
How to Fix It
Test the bake igniter.
1. Turn off power and gas.
2. Remove the oven floor and the burner cover to see the bake burner and igniter at the very back bottom.
3. Disconnect the igniter wires and check for continuity with a multimeter. No continuity means it's dead.
4. Replace it (same part as the oven igniter, often WPW10532497).
If That Didn't Work
The oven control board may not be sending power to the bake circuit. This requires advanced troubleshooting and likely a board replacement.
Heads Up
The broiler uses a separate igniter. The fact it works confirms gas supply is fine, isolating the problem to the bake system.