Combine the butter, sugar, brown sugar, baking soda, salt, flour and oats.

Press half of the mixture into a parchment-lined 9x13" pan and bake.

Make the filling by mixing cream cheese, sweetened condensed milk, vanilla and an egg yolk.

Spread the cream cheese filling over the crust and then sprinkle with blueberries.

Sprinkle with the remaining oat mixture and bake!