Preheat oven to 300 degrees Fahrenheit and line a baking sheet with parchment paper. Set aside.
In a mixing bowl, add melted butter, flour, brown sugar, granulated sugar, and everything bagel seasoning. Mix with a hand mixer until mixture clumps together and forms small balls. Pour out onto prepared baking sheet and spread into an even layer.
Bake for about 15 minutes, or until edges are lightly browned. Remove from oven and allow to cool completely before adding to your ice cream.
In a large bowl, add cream cheese. Blend with a hand mixer until creamy. Add sweetened condensed milk (and optionally, vanilla extract) and mix until incorporated.
In a separate bowl, whip heavy cream until stiff peaks are achieved, up to 3 minutes. Gently fold whipped cream into cream cheese mixture until fully incorporated. The mixture should look fluffy.
Last, crumble your cooled streusel into the ice cream mixture and gently fold to incorporate. Pour into a loaf pan (or any six cup freezer-safe container) and spread into an even layer. Optionally, top with a pinch of everything bagel seasoning.
Cover and freeze immediately for 4-6 hours or until firm.
Vanilla extract is optional, but I find that it enhances the sweetness of the ice cream and helps balance the salty streusel flavor.
Homemade ice cream will keep for up to 2 months in the freezer in a tightly sealed container.