Preheat your oven to 350°F. Grease a 10" cast iron skillet well. Set it aside.
In a large bowl, combine the flour, baking soda, salt, and granulated sugar. Whisk together until combined.
Add in the melted butter, sour cream, egg, vanilla extract, almond extract, and milk. Whisk just until everything is combined and the batter forms. Fold in the blueberries.
Pour the batter into the prepared skillet and spread into an even layer. Top with more blueberries, if desired.
Bake the skillet cake for 25-30 minutes, until the top is a light golden brown and the cake springs back to the touch. Allow it to cool for at least 15 minutes before digging in!