Preheat Oven: Set oven to 175°C (350°F). Line baking sheet with parchment paper
Cream Butter and Sugar: Beat softened butter and sugar until light and fluffy
Add Egg: Mix until fully incorporated and smooth
Add Vanilla Extract: Mix until combined
Mix Dry Ingredients: In another bowl, whisk flour, baking powder, and salt
Combine Dough: Gradually add dry ingredients to wet mixture and mix until dough forms
Divide Dough: Split dough into two equal portions
Add Matcha: Mix matcha powder into one portion until evenly colored
Prepare Berry Puree: Cook blended berries over low heat for 5–10 minutes until thick and jam-like. Cool completely before adding to dough.
Add Berry Puree: Gently fold berry puree into the other portion
Create Marble Effect: Lightly swirl the two doughs together without fully mixing
Shape Cookies: Scoop portions onto baking sheet, spacing 2 inches apart, and flatten slightly
Chill Dough: Refrigerate shaped cookies for 20–30 minutes to firm the dough and prevent excessive spreading.
Bake Cookies: Bake at 170°C (340°F) for 12–15 minutes until edges are set and centers remain soft
Cool Cookies: Transfer to cooling rack and cool completely