In a large mixing bowl, beat the butter with an electric hand mixer. When fluffy, add the brown sugar and beat them together for 3 to 4 minutes. Add the egg and vanilla and combine well.
In a small bowl, whisk together the flour, baking powder, baking soda and salt. Add the dry ingredients to the brown sugar mixture and combine until just incorporated. Fold in the cream cheese. Gently stir in the hazelnuts, coconut and chocolate and spread the batter into a lightly greased 8 by 8-inch glass pan. Bake until a toothpick comes out clean and sides just start to pull away from the edge of the pan, about 18 to 20 minutes. Remove from the oven and let cool for 20 minutes before cutting.