Preheat the oven to 180C/350F. Line and grease a springform cake pan and set aside.
In a non-stick pan, add the butter and place it over medium heat. Once melted, add the brown sugar and melt it down. Once melted, remove it from the heat.
Transfer the syrup into the lined pan and place the pears in a single layer.
In a mixing bowl, cream together the butter and sugar until fluffy. Add the vanilla extract and the egg yolks, until combined.
In a separate bowl, beat the egg whites with cream of tartar until fluffy.
In the bowl with butter and sugar, gradually stir through the milk, followed by the flour, baking powder, and salt. Gently fold through the egg whites until combined.
Transfer the cake batter over the pears and syrup and use a rubber spatula to smooth out the top.
Bake the pear cake for 40-45 minutes, or until a skewer comes out clean.
Let the cake cool for 5 minutes, before inverting the cake onto a plate. Let the cake cool completely, before slicing and sercing.
Notes
TO STORE: Leftovers will keep at room temperature, covered, for up to three days. If you'd like the cake to keep longer, store it in the refrigerator for up to one week.TO FREEZE: Place slices of the cake in a shallow container and store it in the freezer for up to 6 months.