In a small sauce pan, place 1/2 cup (120 mL) of the water on the stove with the blueberries, sweetener and salt. Bring it up to a simmer. Simmer until blueberries are soft and mush easily, about 10 to 15 minutes.
While simmering the blueberries, pour the remaining water into small mixing bowl.
As evenly as possible, sprinkle the powdered gelatin over the surface of the water. This will allow it to “bloom” (the gelatin granules will swell in size, absorbing the liquid from the syrup, helping it to dissolve in the hot water you’ll add). Spreading it evenly helps to prevent clumping. Allow it to bloom for at least 5 minutes.
Once the blueberries have cooked, puree them in a blender or food processor.
Place a straining device over the and strain the hot blueberry sauce into the gelatin. Whisk until the gelatin is completely dissolved. (Note: It’s not required to strain the blueberries, but it can help get a smoother texture. You can go straight from the blender to the gelatin. The only requirement is that the liquid is hot.)
Pour the blueberry gelatin base into a standard 9-inch (23 cm) cake pan, then place into a refrigerator and allow the mixture to chill for at least 8 hours.
At some point while the blueberry gelatin is chilling, pre-heat your oven to 350 F (177 C).
In a medium mixing bowl, combine the almond flour, coconut flour, sugar replacement, baking powder and salt.
In a separate bowl, whisk together the eggs, almond milk, melted butter and vanilla extract.
Pour the liquid ingredients into the dry ingredients and mix to combine. The batter should look like a pancake batter. You may need to add a bit of water or almond milk to thin it out, depending the brands of the ingredients used.
Grease a second standard 9-inch (23 cm) cake pan.
Add the batter to the cake pan and bake for about 15 to 18 minutes, or until the cake is golden and puffy. Remove and set on a cooling rack to cool.
Now, before continuing to the next step, make sure that your blueberry gelatin is completely solid and chilled all the way through.
In a small sauce pan, place the 1/4 cup (60 mL) of the almond milk, cream, sweetener, vanilla and a dash of salt on the stove and bring it up to a point just below a very low simmer.
While waiting for the cream mixture to heat up, place the remaining 3/4 cup (180 mL) almond milk into a mixing bowl.
As evenly as possible, sprinkle the powdered gelatin over the surface of the almond milk. Allow the gelatin to bloom for 5 minutes.
Once the cream mixture is hot and the gelatin has bloomed, pour the hot cream mixture into the bowl with the gelatin and whisk until the gelatin is completely dissolved.
Quickly whisk in the room temperature cream cheese into the gelatin mixture. This is now a cream cheese panna cotta base.
Pour the panna cotta base over the top of the blueberry gelatin.
Carefully lay the thin vanilla cake over the top of the panna cotta base. Press it into the base, so that it a little bit of the panna cotta base is visible around the edges. Make sure the cake is also pressed evenly over the bottom of the dessert.
Place the dessert into the refrigerator to chill for at least 8 hours.
Once the cake is chilled all of the way through, remove it from the fridge and VERY carefully submerge the base of the cake pan in a large bowl or sink filled with hot water. DO NOT let the water flow over the rim of the pan, but you do want as much of it submerged under the water, as possible. The goal is to melt the very thin outer layer of jello, by warming the surface of the mold. This will take about 30 to 90 seconds, depending on the thickness and material of the pan. Test by pushing down on the edge of one side of the gelatin. You should see it easily separate from the edge of the mold.
Once the gelatin easily separates from the edge of the mold, place your serving plate, upside down, over the top of the mold’s base. Quickly flip the platter and cake pan upside down, then gently wiggle and lift the mold off the cake. The cake should slide easily out of the mold onto the platter.
Slice and serve!