Prepare Mango Jam: In a medium saucepan over medium-low heat, combine 200g of frozen mangoes with 1 tablespoon of white sugar. Cook until the mangoes soften and begin to break down, about 5-7 minutes. Mash the mango mixture until smooth and cook for an additional 5 minutes until thickened. Remove from heat, let cool, and refrigerate while you prepare the cookie dough.

Prepare Coconut Sticky Rice: Soak ¼ cup uncooked sweet rice in boiling water for 20 minutes. Drain the rice and transfer to a saucepan. Add ⅓ cup of coconut milk and cook over low heat until the rice is slightly underdone, approximately 10-12 minutes. Stir in 3 tablespoons of sweetened condensed milk, mixing until sticky. Remove from heat and let cool.

Make Cookie Dough: In a large mixing bowl, cream together 113g of softened unsalted butter, 100g of light brown sugar, and 50g of white sugar until light and fluffy, about 3-5 minutes. Add in 1 large egg yolk, ½ teaspoon of vanilla extract, and 1 tablespoon of reserved coconut cream, mixing until well incorporated.

Combine Dry Ingredients: To the butter mixture, sprinkle in ½ teaspoon of baking soda, ¼ teaspoon of salt, and 180g of all-purpose flour. Stir gently until just combined. Chill the dough in the refrigerator for 30 minutes.

Assemble and Bake: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Using a cookie scoop, portion the chilled dough onto the tray, spacing 2 inches apart. Add dollops of the chilled mango jam and coconut sticky rice on top of each cookie.

Bake to Perfection: Bake for 13-15 minutes, or until the edges turn golden brown and the centers are set. Let cool on the tray for 5 minutes before transferring to a wire rack.