Heat 10 tbs of butter over medium high heat until melted. Continue to cook, swirling until butter has an amber colour and nutty smell (about 3 minutes). Remove from heat, pour into heat safe bowl, and add remaining 4 tbs butter, stirring till melted. Leave to cool for 15 minutes.
Use the time to preheat oven to 175C (350F) and line two cookie sheets with parchment paper. Prepare shallow dish with 1/4 cup sugar and 1/4 cup brown sugar. Use fingers to mix together.
In a medium bowl whisk together dry ingredients (minus salt and remaining brown sugar).
Add the remaining brown sugar and salt to butter bowl. Once combined add egg and egg yolk. Finally stir in dry ingredients until just combined.
Roll dough into 24 balls, coat in sugar mixture and place on baking tray
Bake for 12-14 minutes. Do not over bake. Cookies will appear underdone. Cool for 5 minutes on baking tray. Press one egg into the center of each cookie. Transfer to wire rack to finish cooling.