Preheat the oven to 350°F (175°C) and grease your cake pan to prevent sticking.
In a large mixing bowl, whisk together the sifted flour, granulated sugar, ground cardamom, and sea salt until evenly combined.
Add the melted butter, eggs, and vanilla extract to the bowl and whisk until the batter is smooth and slightly creamy, about 1-2 minutes.
Gently fold in the sliced apples, distributing them evenly through the batter with a spatula.
Pour the batter into the prepared cake pan, smoothing the surface with the back of a spatula.
Bake in the preheated oven for about 50 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Slice the cooled cake with a bread knife, revealing tender apple layers inside a fragrant crumb with specks of cardamom.
Serve slices on their own or with a dusting of powdered sugar for a comforting autumn treat.