Chocolate Chunk Cookies Bars - Petites Choses

Ingredients

• ¾ cup plain flour, (90 g)
• ¼ tsp baking powder
• ¼ tsp baking soda
• ¼ tsp fine sea salt
• ¼ cup unsalted butter, (60 g)
• ¼ cup dark brown sugar , (55 g)
• 3 tbsp granulated sugar, (45 g)
• 1 large egg yolk
• ½ tsp vanilla extract
• 115 g dark chocolate, chopped (70% cacao)
• flaky sea salt, to sprinkle