Line a 9x9 baking pan with parchment paper.

In a large bowl add the flour, salt and sugar. Add the softened butter and beat together with a hand mixer until it takes on a sandy texture. There will be some larger bits of butter still there. Add in the egg yolk and 2 tablespoons half and half. Beat together until completely combined. The dough should come together and look a bit like sugar cookie dough. If not, add the additional tablespoon of half and half and try again. Put the dough into the prepared pan. Press all the dough down evenly across the bottom of the pan.

Cover and refrigerate at least 30 minutes or up until overnight.

Bake at 400 degrees for 12-15 minutes or until very lightly browned along the edges. Remove from the oven and lower the temperature to 350 degrees. While it cools make the filling.

Stir together the melted butter and sugar. Add in the cocoa powder and stir together. Stir in the beaten eggs. Add in the flour, salt and baking powder and stir just until moistened. Add ¼ cup chocolate chips to the batter.

Pour the batter on top of the prepared crust, spreading it out evenly. Top with remaining ¼ chocolate chips. Bake at 350 degrees for 25-30 minutes. The edges should look set, and a toothpick inserted in the middle will still come out with moist brownie crumbs.

After the brownie bars have completely cooled, cut into squares or rectangles as desired. I recommend using a sharp kitchen knife to cut through the crust smoothly. Sprinkle with powdered sugar.