Working with frozen butter is best. I like to grate my butter ahead of time and freeze it after grating. It only has to freeze for about 10 minutes before using, so I do this step first while doing the next steps.
Preheat oven to 425. Line a baking sheet with parchment paper.
Put 3/4 Tbsp vinegar in a measuring cup, and then add milk up to the 3/4 cup line. This is essentially making buttermilk, so you can just use 3/4 cup buttermilk if you have that on hand. Let the vinegar sit in the milk for five minutes.
In a large mixing bowl, combine 2 cups flour, 3 Tbsp cornstarch, 1 Tbsp baking powder, 1/4 tsp baking soda, 1 Tbsp sugar, 1 tsp salt, and 2 Tbsp Everything Bagel Seasoning. Stir to combine
Add the 10 Tbsps of frozen, grated butter to the dry mixture, and combine together using a pastry blender or two knives. Your mixture will have pea-sized chunks of butter in the flour mixture.
Add the buttermilk (milk and vinegar) to this mixture and stir with a spatula. It will be a shaggy mess. Do not over-mix.
Lightly flour your countertop or cutting board, and turn the dough out onto the surface. Gently shape the dough into a rectangle 3/4" thick.
Using a sharp knife or bench scraper, cut the dough into thirds. Put 7-8 small teaspoon-sized dollops of cream cheese on one of those thirds. You can estimate the size.
Stack one of the 1/3 layers on top of that and add more dollops.
Stack the final 1/3 on top of that, and press into a rectangle 3/4" thick.
Repeat the process above: Using a sharp knife or bench scraper, cut the dough into thirds. Put 7-8 small teaspoon-sized dollops of cream cheese on one of those thirds. You can estimate the size. Stack one of the 1/3 layers on top of that and add more dollops.
Stack the final 1/3 on top and press into a 1/2" square this time. Cut this square into 9 equal pieces (3x3).
With a thin spatula or bench scraper, transfer the biscuits to the baking sheet, leaving a couple of inches between each biscuit.
Bake for 13-15 minutes or until the biscuits are lightly golden on the top and bottom. These biscuits are best directly out of the oven, after only a couple of minutes to cool.
As mentioned, these are great straight out of the oven. If I want to reduce the prep time for a morning bake, I often mix up the dry mixture and make the buttermilk the night before. I also grate and freeze the butter the night before. Then, in the morning, I simply need to do the final mixing and stacking.
Freezer Instructions: Again, these are best served out of the oven, so I like to bake the dough rather than bake the biscuits. The fully prepped biscuits can be frozen, unbaked, for up to 3 months. They can be baked straight out of the freezer, adding a few minutes of time to the bake.