Preheat the oven to 170°C (340°F) and grease and line your cake tin with parchment paper.
Sift together the flour, ground ginger, cinnamon, baking soda, and salt in a bowl.
Whisk together the melted butter, light brown sugar, milk, egg, and dark treacle until smooth in another bowl.
Gradually add the dry ingredients to the wet mixture, being careful not to overmix.
Gently fold in the diced pears until evenly distributed throughout the batter.
Pour the batter into the prepared tin and bake for about 35–40 minutes or until a skewer inserted comes out clean.
While the cake bakes, combine golden syrup, butter, and brown sugar in a saucepan over medium-low heat until smooth.
Once baked, poke holes in the top of the warm cake and pour the warm glaze over it immediately.
Allow the cake to cool slightly before slicing and serving.