Begin by preheating your oven to 350°F (175°C) and line a cupcake tray with liners.

Start with the vanilla sugar: In a small bowl, combine the granulated sugar with the seeds from the vanilla bean. If you’re new to working with vanilla beans, make sure to watch the accompanying video for guidance. Use the back of a spoon to press and mix, breaking up the seed clumps and infusing the sugar with a deep vanilla essence. Set this fragrant mixture aside.

In a large mixing bowl, or the bowl of a stand mixer, sift together the cake flour, baking powder, baking soda, and salt. Once combined, add in the prepared vanilla bean sugar and mix briefly to integrate.

Add the softened butter to the dry ingredients, and beat on medium-low speed for three minutes. The mixture will resemble a fine, crumbly texture due to the minimal amount of butter.

In a separate bowl, whisk together the eggs, sour cream, canola oil, and vanilla extract until the mixture is smooth and well combined.

Gradually pour the egg mixture into the flour mixture, beating on medium speed until the batter just comes together. Slowly incorporate the whole milk, mixing on low speed until fully combined. The batter will be thin and liquid-like, which is exactly how it should be.

Spoon the batter into the prepared cupcake liners, filling each just over halfway.

Bake in the preheated oven for 14 minutes, then check for doneness. The cupcakes are ready when a toothpick inserted in the center comes out clean or with only a few crumbs. They should appear pale with visible specks of vanilla bean and should not develop a golden brown color. If not done, continue to bake in two-minute increments, testing after each interval.

Once baked, promptly remove the cupcakes from the baking tin and allow them to cool on a wire rack or your countertop if you don’t have one. Let them cool completely before frosting or serving.