Preheat your oven to 350°F (175°C). Grease an 8-inch round cake pan or line it with parchment paper.
In a medium-sized bowl, whisk together the almond flour, sugar substitute, baking powder, and salt.
In a separate bowl, beat the eggs until well combined. Add the melted butter, almond milk, vanilla extract, and almond extract (if using). Mix until smooth.
Add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to overmix.
Pour the batter into the prepared cake pan and spread it evenly with a spatula.
Bake in the preheated oven for 25-30 minutes, or until the cake is golden brown and a toothpick inserted into the center comes out clean.
Remove from the oven and let the cake cool in the pan for about 10 minutes. Then transfer it to a wire rack to cool completely.
Once cooled, you can serve the cake as is or with a topping of your choice, such as fresh berries or a dollop of sugar-free whipped cream.