D+ over C+ (augmented triad over augmented triad a whole step apart).
C           E           G♯    A♯          D           F♯
1           3           ♯5    ♭7          9           ♯11

Parent scale is whole tone.
C     D     E     F♯    G♯    A♯
1     2     3     ♯4    ♯5    ♭7

Related chords
| A♭7 | B♭7 | C7 | D7 | E7 | F♯7 |