Grease a loaf pan, line it with parchment paper, and lightly grease the paper as well as the exposed sides.
In a bowl, whisk together the flour, baking powder, salt, and cardamom.
In the bowl of a stand mixer fitted with the paddle attachment, mix the sugar, butter, oil, and extracts on medium speed until you achieve a pale and creamy mixture, about 2 minutes.
Add the eggs one at a time, beating on medium speed after each addition until the egg is well incorporated.
Add the flour mixture and mix on low speed until everything is well combined, about 30 seconds.
Scrape down the sides of the bowl and mix one last time to ensure the batter is smooth.
Add the blueberries almost all into the bowl (keep 1 to 2 tablespoons aside) and mix until they are well distributed.
Pour the batter into the prepared pan and spread it into an even layer. Sprinkle the top with the remaining blueberries.
In a small bowl, mix the topping ingredients, then evenly sprinkle this mixture over the batter.
Bake the blueberry cake for 55 to 65 minutes, covering it with aluminum foil if necessary, until a toothpick or the point of a knife inserted in the center comes out clean and the internal temperature reaches at least 93 °C on a digital thermometer.
