Preheat the oven to 350°F (175°C).

Brown the butter in a saucepan over medium heat, stirring frequently until it becomes nutty and golden brown, about 5-7 minutes. Let it cool slightly before using.

Mix together the browned butter, brown sugar, and granulated sugar in a large bowl until smooth and well combined.

Whisk together the eggs and heavy cream in a separate bowl, then incorporate it into the butter and sugar mixture.

In another bowl, whisk together all-purpose flour, salt, baking powder, and baking soda. Gradually add this to the wet ingredients, mixing until just combined.

Fold in the fresh blueberries gently, then dollop in blueberry preserves and swirl gently for a marbled effect.

Pour the batter into a greased cast iron skillet, spreading it evenly.

Prepare the streusel topping by mixing flour, sugar, and cold butter together until crumbly, then sprinkle it over the batter.

Bake for about 25-30 minutes, or until the edges are golden and the center is slightly gooey.

Cool the skillet for a few minutes before serving warm with a scoop of vanilla ice cream.