ESP32 Proofing and Holding Base:
My easy to bult and use 'Proofing and Holding Base' let your bread dough rise perfectly and can also be used well as a 'Yogurt Maker' and/or 'Chocolate Melter'. Design and build your own (foldable) cabinet for this project. I use a flat foldable cardboard box, without bottom, that fits in a kitchen drawer. I cut the folds and then made it foldable with tape. But panels and lid with Velcro might also be a good idea. Mounting in an existing and suitable cabinet is of course also a good option.
NOTE: If higher temperatures are used, thermally insulate the plastic parts and install a reflective base plate between the/or additional M8 spacers. The maximum temperature to be reached can be changed in the software, limited by the PTC thermistor Heating plates 50W/80°C.
in code:    const uint8_t tempMax = 50;  // max 80*C
But be aware that mains voltage is life-threatening.

Three external libraries are used:
Download and install:
   Dlloydev: QuickPID
   Links2004: WebSockets
   Bodmer: TFT_eSPI
TFT_eSPI:
Copy these two header files
    ...\Proofer\more\User_Setup_Select.h
and
    ...\Proofer\more\User_Setup.h
to
    .../Arduino/libraries/TFT_eSPI-master/
Do not forget this, otherwise you will not see anything on the display!
WebSockets:
If on compile time: "sha.h" compiler warning change these line in WebSockets.cpp
    #if ESP_IDF_VERSION_MAJOR >= 4
    #include <sha/sha_parallel_engine.h> //<esp32/sha.h>
    #else
    #include <hwcrypto/sha.h>
    #endif

Connection diagram in Fritzing:
Open  ...\Proofer\more\Proofer.fzz or ...\Proofer\more\Proofer.png
    (click thumbnail)
Attention: An ESP32 cannot work simultaneously with USB and an external power supply, the ESP32 will be broken. Don't forget to use the power jumper.
Hint: Place the power jumper, with a striking color, directly under the ESP32 USB connector.

Method of heating:
Up to 8°C below the target temperature both elements are ON, then the PID controller switches them ON/OFF alternately as required.
in code:    const uint8_t threshold = 8; // 2 or 1 plate(s) on heat ON

OTA firmware-update:
Firmware-update? It's not necessary to open the controller box, upload the new firmware via OTA.
The OTA-Hostname is 'proofer'.
Don't forget to set your SSID and PASSWORD in the software before the first USB upload.