Teensys are available in 8-bit and 32-bit versions, the hardware has a bread-board friendly footprint, there are a ton of Teensy libraries available, and they can also run standard Arduino libraries.

[Scott-28] recently sent in a particularly well-documented project that turned an antique rotary phone into a digital kitchen timer using an internal Arduino.

The programmable timer features and up counter, down counter, and point accumulator that can be programmed manually using only one on-board button, or digitally with your Arduino or Raspberry Pi.