Bb Augmented Major 7th, 1st inversion (D in the bass)
Also written as Bbaug(maj7)/D.
Notes, from the bass up
D (bass)F#AA#
The same notes as Bb Augmented Major 7th (D, F#, A and A#), rearranged so D is the lowest note. Use it to move between chords with smaller jumps across the keyboard.