Adafruit Grand Central M4 Express features the Microchip SAMD51 and a 120MHz Cortex M4 with floating point support. The Grand Central provides enough pins to make it in the form of the Arduino Mega. The board has a massive number of pins, tons of analog inputs, dual DAC outputs, 8MBytes of QSPI flash, an SD card socket, and a NeoPixel.
Cortex M4 core running at 120MHz
Floating point support with Cortex M4 DSP instructions