Combine the the Greek Yogurt, Eggs and Vanilla Extract.In a seperate bowl, mix all the dry ingredients: Flour, Brown Sugar, Baking Powder, Baking Soda and Salt.
Whisk in the melted butter to the dry ingredients then slowly add the Yogurt/Egg mix. Whisk until all combined and lumps free.
Peal and cut the Pears in small cubes.
Pour the Cake Batter in a rectangular baking tray lined with baking paper. Cover with the Cubed Pears.
In the bowl of your food processor, quickly pulse all the Flour and all the Spices to mix them in. Add the Orange Zest and Butter cut in small pieces. Pulse until crumbs form (see note 1).
Evenly cover the Cake Batter and Pears with the Spiced Crumbs.
Bake at 180'C for 20 to 25 minutes or until the crumbs look golden-brown.
1. If you do not have a food processor, simply mix in all the ingredients in a large bowl then incorporate the orange zest and butter. To make the crumbs, rub the dry ingredients and butter between your fingers and palms.