Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour your cake tin, or line it with parchment paper for easy removal.
Prepare Dry Ingredients: In a medium-sized bowl, whisk together the einkorn flour, baking powder, baking soda, and salt. Set aside.
Cream Butter and Sugar: In a large bowl, beat the softened butter and sugar together using an electric mixer until light and fluffy.
Add Eggs and Vanilla: Add the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract.
Combine Wet and Dry Ingredients: Gradually add the dry ingredients to the wet mixture, alternating with the milk. Start with the dry ingredients and end with the milk. Mix until just combined.
Add Optional Ingredients: If you're adding chopped nuts or berries, gently fold them into the batter.
Bake the Cake: Pour the batter into the prepared cake tin and spread it evenly. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Cool the Cake: Let the cake cool in the pan for 10 minutes before transferring it to a cooling rack to cool completely.
Serve: Once fully cooled, frost with your favorite frosting or serve plain. Enjoy!