Preheat the oven to 400°F and either butter a pie plate or well oil a cast iron pan.
In a medium bowl, combine the eggs, vanilla, whipping cream, and pinch of salt. Whisking until frothy and light.
Add the Splenda, flour, and spices and whisk until well blended.
Pour into the pan and sprinkle with the blackberries. Use a spatula to gently tap them into the batter.
Sprinkle with the almonds, again using a spatula to press lightly into the batter.
Give a light dusting with fresh ground nutmeg and ground cardamom.
Bake for 30-35 minutes until golden brown. (I found it was about 30 minutes in a convection oven.)