Prepare the Mango Jam: Cook frozen mangoes in a pot over medium heat for 5-7 minutes, mash, and simmer until thickened.

Cook the Sticky Rice: Soak sweet rice in boiling water for 30 minutes, then steam for 20-25 minutes and mix with coconut milk and sweetened condensed milk.

Make the Cookie Dough: Cream butter and sugars, then add egg yolk, egg white, and vanilla. Combine with dry ingredients.

Chill the Dough: Cover and refrigerate for 30 minutes, then preheat the oven to 350°F (175°C).

Assemble & Bake: Scoop dough onto a baking sheet, add sticky rice and jam, and optionally top with sesame seeds or salt.

Bake and Cool: Bake for 13-15 minutes until golden, then cool on a wire rack.