140g Butter
100ml brandy
300ml milk
2 large egg yolk
175g light soft brown sugar
150ml double cream

Tried after nearly three week steep, brandy still a tiny bit harsh but it's come together nicely.

Definitely needs minimum of three weeks steep IMO, it should continue to smooth out if steeped longer.

I think you could probably increase the Brandy a touch for more of a boozy kick YMMV!