Adjust the oven rack to the lower middle position and pre-heat the oven to 350ºF (180ºC). Lightly butter a 9-inch (23cm) springform pan and line it with parchment/baking paper.

In a large bowl, whisk together the sugar, melted butter, oil, eggs, milk, yoghurt and vanilla until well combined.

In a separate bowl, whisk together the gluten free flour blend, almond flour, baking powder, xanthan gum and salt.

Add the dry ingredients to the wet, and whisk everything together into a fairly loose, smooth batter with no flour clumps. Set it aside while you prepare the almond frangipane.

In a large bowl, mix together the sugar, melted butter, eggs, vanilla and almond extract until well combined and smooth.

Add the almond flour and salt, and mix well until smooth. Transfer the frangipane to a piping bag with its end cut off.

Pour the almond cake batter into the lined springform pan and smooth out the top.

Pipe the almond frangipane in an even layer on top of the cake batter.

Sprinkle evenly with the flaked almonds.

Bake at 350ºF (180ºC) for about 60-70 minutes. If the flaked almonds on top start browning too much, cover the cake with a sheet of aluminium foil and continue baking until done.

Allow the cake to cool in the springform pan for about 15 minutes before removing it from the pan onto a wire rack to cool.

Dust it generously with powdered/icing sugar before slicing and serving.