Preheat oven to 200 degrees. Heat waffle iron to medium high heat.
In a large bowl whisk together Gluten Free Flour, sugar, sea salt and baking soda. In a blender, combine hazelnut spread and butter and process for 1 minute. Add yogurt, milk and eggs and blend for another minute. Add liquid mixture to dry mixture and stir just until the batter is combined.
Brush waffle iron with butter and add about ¾ cup (for a Belgian waffle iron) of batter to the waffle iron. Cook until golden brown. Transfer to the warm oven and continue with remaining batter.
While the waffles are cooking heat the hazelnut spread in a small saucepan over low heat. Whisk until melted. (You can add a little milk to make it thinner if you would like.) Drizzle over warm waffles and serve.