What is "serradura"

Serradura , also known as sawdust pudding, or Macau pudding, is a well-known dessert of Macau, which shows a layered outlook with a simple combination of whipped cream and crumbled Marie biscuit. The name serradura is a Portuguese word for “sawdust”, which refers to the way the biscuits look in the pudding, as they are crushed very fine into crumbs.