
This Keto Pineapple Upside-Down Cake is an easy, moist, and buttery childhood favorite upside down cake revisited sugar-free and gluten-free, with a delicious pineapple caramel flavor.
Preheat oven to 350°F (180°C).
Peel the fresh pineapple and cut it into thin rings of about 3 mm/0.1 inch thickness, using a sharp knife (remove the hard center part of each ring using a round shape. A ring is about 1.2 oz.
Pat dry each pineapple ring into some absorbent paper to remove extra juice that could release into the cake and make it too moist.
Prepare the topping in a small bowl by beating softened butter and brown erythritol to form a creamy paste.
In a large mixing bowl, using a manual whisk, beat eggs, erythritol, unsweetened almond milk, baking powder, salt, vanilla extract, pineapple extract, and melted butter. Make sure the melted butter is not too hot, or it can cook eggs and form lumps.
Store the cake in a sealed cake box in the fridge for up to 3-4 days.