Step 1

Preheat the oven to 350 degrees F (175 degrees C). Butter a 12x17-inch rimmed baking sheet.

Step 2

Beat condensed milk, coconut milk, and melted butter together in a large mixing bowl until combined. Add eggs, 1 at a time, and beat until combined. Add macapuno, 1 jar at a time, and beat until combined. Gradually beat in mochiko flour. Beat in brown sugar; beat in vanilla extract. Pour batter onto the prepared baking sheet.

Step 3

Bake in the preheated oven until top is golden brown and sides are slightly dark brown, 45 to 50 minutes.

Step 4

Allow to cool, about 20 minutes, before loosening the sides and cutting into squares.