In a large bowl, cream the butter and both sugars together until light and fluffy – about 3 minutes. Add the vanilla and eggs; mix well. Add the flour, baking powder, baking soda and salt. Mix on low speed until just combined. Stir in the chocolate chunks. Gently stir in the Nutella® until it is swirled throughout the dough, being careful not to over-mix. Scoop out generous tablespoon-sized portions of dough onto lined baking sheets. Lightly sprinkle each ball of dough with sea salt and then bake in a 350oF oven for 8-10 minutes or until the edges are lightly browned. Allow the cookies to cool for 10 minutes on the baking sheets and then remove to a wire rack to continue cooling. Cooled cookies can be stored in an airtight container for up to three days.