Preheat oven to 360°F (180°C). Grease sides of a 8-inch round cake pan (solid, not springform) with butter and line the bottom with baking parchment.

To make the caramel, put the sugar and lemon juice in a small heavy-bottomed saucepan and add enough water just to wet the sugar. Place over low heat and swirl gently as the sugar dissolves and the caramel begins to turn golden.

When deeply golden, take it off the heat and add the orange juice. Return to heat and boil rapidly for 3 minutes. Whisk in the butter bit by bit, then pour the caramel into the base of the prepared cake pan.

To make the cake batter, cream the butter, sugar, and orange zest until light and fluffy, scraping down the sides of the bowl frequently. Add the eggs one at a time, beating in each egg completely. Whisk together the ground almonds, cornmeal, baking powder, and salt in a bowl then add to the butter and egg mixture.

Arrange the orange slices on the caramel in the cake pan then dollop the cake batter over the top. Using a small offset spatula, gently spread and level the top, being careful not to disturb the orange slices.

Bake in the middle of the oven for 1 hour, a skewer inserted should come out clean. Allow to cool for 30 minutes then carefully invert onto a wire rack to cool completely.

This cake is best after it has rested for several hours, uncovered so that the crust can dry a bit. A loose piece of parchment is sufficient cover for the cake as it exists in the kitchen for a few days.

Serve each slice with a dollop of cream.