Grease and line the base and sides of a 20cm round baking tin with baking paper. Use a non-springform tin if possible.
Bake at 180° for about 1 hour, or until the top springs back to touch and a skewer inserted comes out with a few crumbs attached (if you used a spring form tin, set something in the oven underneath to catch any drips).
Set aside to cool for 30 minutes. Turn the cake out onto a wire rack or serving plate so the almonds are on top and remove the baking paper carefully. If any almonds fall off, just set them back into place. Leave to cool completely before serving. Cut with a serrated knife for sharp slices through the almond topping.