Pre-heat a fan forced oven to 160℃.
Line the base and sides of the cake tin with baking paper.
Peel and slice the pears, cover in lemon juice to stop the browning and set aside until needed.
Add 1 cup of brown sugar and 150 grams of softened butter to a large mixing bowl and beat with the electric mixers until smooth and creamy (about 2 minutes).
Add eggs, vanilla and drained juice from the pears and beat again until well combined (about 30 seconds).
Now add the dry ingredients: self-raising flour, cinnamon, ginger, nutmeg and baking powder and beat until well combined (about 2 minutes).
Set the cake batter aside and start on the caramel.
Heat a saucepan or small fry pan over medium heat and add the butter until mostly melted, then add the sugar and cook together until is starts to bubble.
Take off the heat, stir and quickly pour caramel into the base of the cake tin.
Place pears in an attractive pattern on top of the caramel and then pour over the cake batter (make sure to work quickly, so the caramel doesn't spill out of the tin).
Bake in the oven for 40 minutes. Use a knife or a skewer to test if the batter is done by inserting it into the centre of the cake, if it comes out clean its ready.
Allow the cake to sit for 5 minutes, before carefully flipping it. Do this by covering the top of the cake tin with a large plate and quickly flipping it so the plate ends up on the bottom and tin is upside-down on top. Use tea towels or oven gloves so you don't burn your hands.
Allow the cake to sit for 5 minutes before removing the cake tin from the top.
Serve warm or at room temperature with freshly whipped cream, crème fraiche or vanilla ice cream.