GLUTEN-FREE STICKY PEAR, DATE & GINGER CAKE

175g unsalted butter, softened, plus extra for greasing • 9 Waitrose LoveLife Medjool Dates, pitted and roughly chopped • 3 balls stem ginger, roughly chopped, plus • 1 tbsp stem ginger syrup • 4 tbsp maple syrup • 3 large eggs • 200g ground almonds • 75g rice flour • 1 tsp gluten-free baking powder • 1 tsp ground ginger • Pinch of salt • 2 conference pears, peeled, cored and cut into 2cm chunks • 3 tbsp icing sugar