Update - The route we climbed (see below) was not the first ascent of a new route, but in stead the second ascent of a route called Mia’s Fashion Parade at grade VI, 6. This route will feature in a new guidebook, due out soon. Many thanks to Mark 'Baggy' Richards for providing this information.
Not only is Cwmglas Bach a snow-holding area, being north facing, but it also presents some rocky pinnacles, which can provide both mixed climbing and ice climbing. Because of the conditions, we (Steve Joynson & I) opted for mixed climbing.
Specifically, Craig y Cwmglas Bach is broken into two pieces of a rock. The two pieces of rock are bisected by a gully, namely The Gully III/II *. To the left of The Gully is a pillar of rock, namely The Pillar, and to the right of The Gully is extensive crag. We climbed on The Pillar.
More specifically, The Pillar has two distinct chimney features. The left chimney on The Pillar has been climbed before, being named Snuff Box IV, 5 (see Welsh Winter Wiki for the route description). We climbed the right chimney of The Pillar. This route provided mixed climbing at grade VI, 6. From information gathered so far, it is possibly a new mixed climbing route, or may be an archaic, traditional climbing route.