Set the oven to 350°F (175°C) and line a muffin pan with cupcake liners to make cleaning up a breeze.
In a medium bowl, whisk together your cake flour, sugar, baking powder, baking soda, and salt until everything is light and airy. Set this aside for now.
In a larger bowl, mix together your buttermilk, milk, vanilla extract, vegetable oil, egg, and egg white. Whisk it all until smooth, it’ll give your cupcakes that soft, tender texture everyone loves.
Slowly add the dry ingredients to the wet mix, whisking until everything is just incorporated. Don’t overdo it, your batter should still be a little fluffy, not dense.
Scoop the batter into your cupcake liners, filling each about two-thirds full. Pop them in the oven for 20-22 minutes, or until a toothpick inserted comes out clean. Give them a gentle press in the center, they should bounce back.
While the cupcakes cool, prepare the strawberry filling. Combine diced strawberries and strawberry jam in a small bowl. The jam holds everything together while adding extra sweetness.
Once the cupcakes have cooled, use a small paring knife to cut a hole in the center of each cupcake, being careful not to go all the way through.
Carefully Take off the top of the cupcake and set it aside for later.
Spoon about a tablespoon of the strawberry filling into each well.
Gently place the cupcake tops back on, covering the delicious filling inside.
To make the frosting, whip the chilled heavy cream and vanilla pudding powder together until it forms soft peaks. It should be airy, soft, and firm enough to maintain its shape.
Pipe the whipped cream generously on top of each cupcake, creating a beautiful swirl. Finish off with a couple of fresh strawberry slices on top for that perfect touch of sweetness.