Start by preheating your oven to 350°F (175°C). Line a standard muffin tin with foil liners (avoid paper liners, as they might not hold up well when soaked). This recipe makes about 16 cupcakes, so you may need to bake them in batches.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside while you prepare the wet ingredients.

In a microwave-safe bowl, melt the butter. Once melted, whisk in the sugar and continue whisking until the mixture is no longer warm to the touch. Add the egg, buttermilk, and vanilla extract, whisking until everything is well-combined.

Add the dry ingredients into the wet mixture. Stir until just combined, being careful not to overmix. Aim for about 20-30 strokes with the whisk, until the batter is smooth but not overworked.

Scoop the batter evenly into the muffin tin, filling each cup about two-thirds full. Bake the cupcakes for 14-16 minutes, or until a toothpick inserted in the center comes out clean. Let them cool on a wire rack.

Once the cupcakes have cooled, use a thin skewer to poke holes all over the cupcakes—this helps the milk mixture soak in. Prepare the milk mixture by whisking together the sweetened condensed milk, evaporated milk, and heavy cream. Slowly drizzle the mixture over each cupcake, allowing it to soak in. You’ll want to use about 2-3 tablespoons of milk mixture per cupcake.

For the topping, whip the heavy cream, powdered sugar, and vanilla extract together until stiff peaks form. Dollop the whipped cream on top of each cupcake and garnish with fresh berries.

Refrigerate the cupcakes for at least one hour, or cover with plastic wrap and chill for up to 12 hours. Serve the cupcakes cold for the best flavor and texture.