1. Take 70 grams of Mary biscuits and use a food processor to grind the biscuits into powder. The finer the better.
2. Put the light cream into a mixing bowl and beat until it is barely flowing. Add condensed milk at this time and continue to beat until there are clear lines that will not disappear. Then add the whipped light cream. Pour the buttercream into a piping bag and set aside.
3. Take an appropriate amount of biscuit crumbs, pour it into the bottom of the cup, and then compact it gently.
4. Squeeze about the same thickness of whipping cream on the compacted biscuit crumbs.
5. Continue to spread a layer of biscuit crumbs on top of the whipped cream, lightly compact it, then squeeze another layer of whipped cream, and repeat this step until the cup is filled.
6. On the last layer of whipped cream, first spread a thin layer of biscuit crumbs to cover most of the cream, then use a flour sieve to evenly sift in the biscuit crumbs.