First, peel your saba bananas and slice them diagonally into ½-inch pieces on a cutting board. Set them aside for now.
In a medium saucepan, combine 2 cups of water with ¼ cup panutsa or your preferred sweetener (coconut sugar or brown sugar works well). Turn the stove to medium heat (175°C/350°F) and bring the mixture to a gentle boil, stirring occasionally to help dissolve the sugar completely.
Once boiling, reduce the heat to low (120°C/250°F) and let it simmer for about 10 minutes until the mixture slightly thickens and becomes syrupy.
Add your sliced bananas to the simmering syrup. Cook them for 5-7 minutes on low heat until they become tender but still hold their shape. Try not to stir too much so the bananas don't break apart.
Remove the saucepan from heat after the bananas are tender. Add ¼ cup chia seeds and stir gently until everything is mixed. If you want, you can add ½ teaspoon vanilla extract for extra flavor.
Cover the saucepan and let the mixture cool to room temperature for about 30 minutes. The mixture will thicken as it cools and the chia seeds absorb the liquid.
When you're ready to serve, place 2-3 tablespoons of the banana-chia mixture at the bottom of a tall glass. If you've refrigerated the mixture, let it come to room temperature first for the best taste.
Fill the glass about ¾ full with freshly shaved ice. If you don't have a shave ice machine, crushed ice from a blender works too.
Pour about ¼ cup milk of your choice over the ice. You can use regular milk, evaporated milk, coconut milk, or any plant-based milk you prefer.
If you want, add some toppings like toasted pinipig (flattened rice flakes) or a drizzle of condensed milk for extra sweetness.
Serve immediately with a long spoon so you can dig all the way to the bottom for those sweet bananas. Mix everything together as you eat or enjoy each layer separately.
The banana-chia mixture can be stored in the refrigerator in an airtight container for up to 3 days, so you can make it ahead of time and just assemble with ice and milk when you're ready to enjoy.