Preheat oven to 350 degrees F. Spray a loaf pan with cooking spray.
Make the streusel topping by combing all of the ingredients and then working the butter into the flour and sugar until it’s crumbly. Set aside.
In a small bowl, combine the cinnamon swirl ingredients, and set aside.
To make the bread, combine the flour, baking soda, and salt in a large bowl and whisk to combine.
In a separate bowl, whisk the egg with the sugar and then add the oil, yogurt, milk and vanilla. Whisk until well combined, then add to the dry ingredients. Stir just until the flour is incorporated.
Pour half of the batter into your loaf pan. Add the cinnamon swirl mixture and then pour the remaining batter on top. Grab a butter knife and run it through the batter, swirling the cinnamon sugar through the batter.
Top evenly with the streusal topping.
Bake for 50 minutes and check to see if a toothpick inserted in the center comes out clean. If not, bake for 5-10 more minutes until it does. If the top is too browned, cover lightly with foil.
When done, let cool completely before removing and slicing.