Alexander Scriabin's "2 Impromptus à la Mazur" Op. 7 beautifully blend the lyrical character of an impromptu with the rhythmic vitality of a mazurka. They showcase Scriabin's early harmonic language and melodic inventiveness.
Requires a sensitive command of rubato and a clear differentiation between melody and accompaniment to bring out the dance-like character.
2 Impromptus à la Mazur (Op.7) is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
2 Impromptus à la Mazur (Op.7) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.