Ingredients: 

Crump topping: 
Plain flour - 1 1/2 cups (195 gms)
Firmly packed light brown sugar -3/4 cup (155 gms)
Powdered Cinnamon 1tsp
Salt 1/4 tsp
Unsalted butter, melted - 10 tbsp (140 gms)

Yogurt Cake:
All purpose flour - 1 2/3 cups (225 gms)
Baking powder  - 1 tsp(4 gms)
Baking soda- 1/2 teaspoon (2 gms)
Salt 1/2 tsp(2 gms)
Powdered cinnamon -1/4 tsp
Instant coffee powder -1/2 tsp (optional)
Eggs -2 large
Oil - any flavorless -1/2 cup (120 ml/gms)
Greek Yogurt -3/4 cup (180 ml/gms) room temperature
Pure vanilla extract -1 tsp (4 gms)
Granulated white sugar -1 cup (200 gms)

Method: 

1. Preheat your oven to 350 degrees F (180 degrees C)
2. Prepare the baking pan ( 8x8 inch) . Butter or spray with a non stick vegetable spray. Line the bottom of the pan with parchment paper.

Crumb Topping:
1. In a bowl add the flour, sugar, ground cinnamon and salt.
2. Then add the melted butter and mix it until all the dry ingredients are just moistened. I used my hand to do so as it was easier.

Yogurt Cake:
1. Take a large bowl and add flour, baking powder, baking soda, salt, ground cinnamon, and espresso powder (if using).
2. In another bowl beat the eggs with a whisk and then add oil, yogurt, and vanilla extract.
3. Stir in the sugar.
4. Add the wet ingredients to the flour mixture. Stir until just combined. the mixture would be sticky and a bit thick.
5. Add the batter into the prepared pan. Evenly scatter the crumb topping on top of the batter with your hand, braking lumps if any.
6. Press lightly so the crumbs adhere to the batter.
7. Place the oven rack in the center of the oven. Bake in preheated oven for about 40 - 45 minutes or until a skewer comes out clean.


Tips: 

1. You can reduce the quantity of overall crumb topping, if you like less of it.
2. We can just make a plain yogurt cake, without topping. Just use a smaller pan.