Preheat the oven to 170°C.
Prepare and measure all ingredients before starting.
Combine the plain flour and baking powder and sift together. Almond flour does not need to be sifted.
Cut the butter into large cubes.
Grease the cake pan with the remaining butter and set aside.
Place the butter and sugar into a mixing bowl.
Beat on low speed until the butter and sugar begin to come together, then increase to medium speed. Beat until the mixture is pale yellow. Scrape down the sides of the bowl as needed to ensure everything is evenly mixed.
Add the eggs one at a time, mixing well after each addition.
Add the milk and vanilla extract. Mix well.
Add the plain flour and almond flour. Beat on low speed until just incorporated.
Pour the batter into the prepared pan. Run a skewer through the batter and tap the pan firmly on the counter to remove air pockets.
Bake between 30 - 40 minutes, adjusting the timing according to your oven.
Test for doneness by inserting a skewer into the centre of the cake. If it comes out clean, the cake is ready.
Remove from the oven and cool on a wire rack before serving.