Add butter to saucepan. Heat over medium heat until butter begins to brown, swirling occasionally. Set aside to cool.
Add egg, dark brown sugar, light brown sugar, and blended granulated sugar to stand mixer. Beat until smooth, about 2 minutes.
Add Greek yogurt, mascarpone cheese, vanilla bean paste, ground cinnamon, baking powder, baking soda and sea salt to sugar mixture. Mix about 1 minute to combine.
Add browned butter to mixer. Beat just until combined.
Remove bowl from mixer. Add flour to sugar mixture and fold flour in with spatula or wooden spoon.
Add roughly half the pecan streusel mixture to cookie dough. Fold in with spatula.
Using a 1-1/2 tablespoon cookie scoop, scoop cookies into small balls, place on cookie sheets, about 3 inches apart. Press down only slightly.
Sprinkle streusel over cookies. Press lightly to adhere.
Bake cookies in preheated oven for 10-12 minutes or until edges are golden.
Remove cookie sheets from oven and place on wire racks to cool.