Begin by creaming the unsalted butter in a mixing bowl until smooth. Add granulated sugar and beat until creamy and light in color. Incorporate the large egg, egg yolk, and vanilla extract until fully combined.

In a separate bowl, whisk together all-purpose flour, baking powder, baking soda, and salt until well mixed. Gradually add the dry mixture to the wet ingredients, blending carefully until just combined.

Gently fold in the frozen raspberries and white chocolate chips into the cookie dough using a spatula, taking care not to overmix.

Scoop the cookie dough into evenly sized balls about 1.5 inches in diameter, and place them on a parchment-lined baking tray. Chill in the freezer for 15 minutes.

Preheat your oven to 350°F (180°C) during the last few minutes of chilling. Arrange the chilled dough balls on a lined baking sheet, spacing them 2 inches apart. Bake for 10-12 minutes until the edges are golden brown.

Remove the cookies from the oven and let them sit on the tray for about 5 minutes, then transfer to a wire rack to cool completely.

Prepare the raspberry glaze by mashing raspberries in a small bowl. Strain to remove seeds, whisk in powdered sugar and milk or water to achieve desired consistency.