Gather the ingredients and preheat the oven to 350°F (180°C). Line a 9x5 inch loaf pan with baking paper. Grease and dust the sides with almond flour if necessary.
In a large mixing bowl, combine the dry ingredients: Almond flour, Erythritol, baking powder, baking soda, and salt. Mix well.
In another bowl, combine the wet ingredients: Eggs, orange juice and zest, melted butter, and vanilla extract.
Gradually add the wet ingredients mixture to the dry ingredients, whisking to create a smooth batter.
Pour the batter into the lined loaf pan and bake in the oven for 30-35 minutes, until a toothpick inserted in the middle of the cake come out clean.
Remove the orange cake from the oven and let it rest until it reaches room temperature.