Teensy 3.2 with pins

Delivery time: Due to the worldwide shortage of chips, this product is not expected to be available again before second half of 2023.
Possible alternative products can be found below.

The Teensy is a breadboard-friendly development board with loads of features in a, well, teensy package. The Teensy brings a 32 bit ARM Cortex microprocessor into the mix so you can do some serious number crunching. You can program for the Teensy in your favorite program editor using C or you can install the Teensyduino add-on for the Arduino IDE and write Arduino sketches for Teensy.

More information is available on the website of Sparkfun and PJRC.