Preheat oven to 400 °F
Sift almond flour with a wire mesh. This is done to ensure a smooth cake.
Line a 9" springform pan with parchment paper
Using stand mixer or handheld mixer mix together the cream cheese and erythritol until well combined. About 1 minute on medium speed.
Scraping down sides often to ensure mixture
Add 5 large eggs, one at a time, mix until incorporated
Add heavy cream, vanilla, salt and orange zest. Mix on medium until smooth.
Add the sifted almond flour gently to the top of the batter. Mix until incorporated.
Pour batter into the springform pan
Poke any air bubbles on the top of the batter with a toothpick. Try to get as much air out as possible.
Push in the pleats so they are not protruding too much into the cake but try not to worry too much about this. The pleats will give the rustic look to the cake.
Place springform pan onto a baking tray and bake at 400°F for 50-60 minutes
If cake does not look burnt on top, place the cake on the highest level in the oven and place oven on broil. Be careful to watch that the parchment paper is not touching the top of the oven as it may burn. Watch the oven closely at this point until the surface of the cake has browned. Remove immediately once the top has burnt.