In a small saucepan, melt together the chocolate and butter, stirring occasionally. Allow to cool for 5 minutes.
In the meantime, beat the eggs and both sugars together in a large bowl until light in color, about 5 minutes. Beat in the salt.
Carefully fold in the melted chocolate mixture using a rubber spatula.
Sift in the flour and baking powder and gently fold in too.
Stir in the milk chocolate chips. Pour into a shallow baking dish and freeze for an hour or until firm.
When ready to bake, preheat the oven to 350°F (175°C) and line three baking sheets with parchment paper.
Allow the dough to stand at room temperature for 5-10 minutes before scooping the cookies with a cookie scoop. Depending on what size cookies you want, scoop 2-3 tablespoon-sized balls onto the baking sheets, set about 2 inches apart.
Bake for 10-15 minutes (depending on the size - check often) or until the edges are looking dry and the tops are crackled. The cookies will still be very soft when finished baking!
Let the cookies cool on the baking sheet for 10 minutes or until they are firm enough to be transferred to a wire rack.
Cool completely before storing in an airtight container.