Blend all the wet ingredients in a blender until smooth.
Mix all the dry ingredients in a large bowl until well combined.
Pour the wet ingredients into the dry ingredients and stir until just incorporated. Do not overmix.
Pour 2/3 of the batter into a greased 8×8" baking pan. Spread the cream cheese gently over the surface. Pour the remaining 1/3 of the brownie batter on top and use a knife to make large swirls through all 3 layers until the top looks lovely and marbled. Do not over-swirl or there won't be any difference between the brownie bits and the cream cheese bits.
Bake at 350F for 30-40 minutes, checking after 30 minutes to see if a knife inserted into the middle of the brownies comes out mostly clean. The longer baking time is needed for a glass or ceramic pan.
Remove from the oven and cool completely before cutting into it. This is important for gluten-free bakes. Store in a sealed container in the freezer, or enjoy right away!