Melt butter and honey in small saucepan.
Whisk flour, baking powder and soda, and salt in large bowl to blend.
Whisk eggs, milk, and sour cream in another large bowl until well blended.
Gradually whisk dry ingredients into wet ingredients until batter is smooth.
Whisk butter-honey mixture into batter and sprinkle with hazelnuts.
Preheat oven to 250 degrees F (121 degrees C - gas mark 1/2). Heat waffle iron and spray with nonstick spray.
Pour 1 cup batter on an 8-inch square waffle iron making four 4-inch waffles (use more or less depending on the size of your waffle iron). Spread batter evenly over grid and close, cooking until waffles are golden brown on both sides.
Transfer waffles to baking sheet and keep warm in oven. Repeat until batter is gone.
Separate waffles into squares and divide among 4-6 plates. Sift powdered sugar over waffles, then drizzle with maple syrup.
If desired, top with berry preserves or a berry coulis, or with chocolate syrup instead of maple.
Note: number of servings and prep and cooking time are estimated.