INSTRUCTIONS

1. Preheat oven to 350°F. Lightly grease a 10-in Bundt pan.
2. Combine ¼ cup butter with 1 cup brown sugar in a small frying pan over medium heat. Stir until mixture begins to melt. Lower heat to medium-low and continue cooking, stirring often, for 5 minutes. Stir in 1 tsp cinnamon, 1 tsp lemon zest and ½ tsp salt until combined.
3. Transfer sugar-mixture to prepared pan, spreading evenly across bottom of pan. Sprinkle 1 cup blueberries on top. Set aside.
4. Combine ½ cup brown sugar, 1 tbsp cinnamon, ¼ cup flour, lemon zest, and 1 tsp salt in a small bowl. Stir in remaining 1 cup blueberries. Set aside.
5. Combine 3 cups flour, baking powder, baking soda and remaining 1 tsp salt in a medium bowl.
6. Whisk sour cream, lemon juice and vanilla together in a small bowl.
7. Using an electric mixer on medium speed, whisk remaining 1 cup butter, granulated sugar and ½ cup brown sugar in a large bowl until light and fluffy, about 3 minutes. Reduce speed to low, add eggs, one at a time, mixing well and scraping down sides of bowl between each addition. Whisk in sour cream-mixture until blended. Add flour-mixture and whisk until just combined.
8. Pour half of the batter evenly into pan. Sprinkle blueberry-mixture over top. Spread remaining batter evenly over top.
9. Combine remaining 3 tbsp brown sugar and 3 tsp cinnamon together in a small bowl. Crumble over top of cake.
10. Bake, in centre of oven, until a wooden skewer inserted into the cake comes out clean, about 45 to 55 minutes. Let rest for 5 minutes on a cooling rack before carefully inverting onto a serving plate. Leave pan inverted for 2 to 3 minutes to allow cake and topping to release.