"Double cream" refers to a type of cream that is richer and thicker than regular cream. It contains a higher amount of fat, which makes it creamier and gives it a silky texture. Full definition
Whisk the 150 ml of double cream until you get soft peaks. (topwithcinnamon.com)
I decided not to top the cake with double cream as I wanted it to keep for as long as possible, so just scattered grated chocolate over the top. (tinandthyme.uk)
Add 1/3 cup of double cream in a slow stream, all the while mixing vigorously. (theloopywhisk.com)