Preheat the oven to 350 degrees F (175 degrees C).

Combine biscuit crumbs, butter, and sugar in a bowl using fingers until well combined. Press mixture into bottom and sides of a tart pan and flatten evenly using a spoon.

Bake in the preheated oven until golden, 7 to 8 minutes. Remove from oven and leave oven on. Allow shell to rest while preparing filling.

Whisk egg yolks and calamansi peel in a bowl on high speed until light and fluffy. Reduce speed to medium and gradually add condensed milk until smooth and thickened. Stir in calamansi juice and mix just until well combined. Pour mixture into tart shell.

Bake in the hot oven until set and not browned, about 10 minutes. Cool on a wire rack until tart reaches room temperature, about 30 minutes. Refrigerate until cool, about 30 minutes more, before serving.

Meanwhile, whip heavy cream and sugar together in a bowl until stiff peaks form.

Slice tart into 6 equal pieces and top with a generous amount of whipped cream.