Preheat the oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners.

Whisk the flour, baking powder, and salt together. Set aside.

Using a handheld or stand mixer fitted with a paddle attachment, beat the butter and sugar together on high speed until smooth and creamy, about 2 minutes. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. Add the eggs and vanilla, then beat on medium-high speed until combined. Scrape down the sides and up the bottom of the bowl as needed. With the mixer on low speed, add the dry ingredients until just incorporated. With the mixer still running on low, slowly pour in the milk, lemon juice, and zest until combined. Do not overmix. You may need to whisk it all by hand to make sure there are no lumps at the bottom of the bowl. The batter will be slightly thick.

Pour/spoon the batter into the liners—fill only 2/3 full to avoid spilling over the sides. Bake for 18-22 minutes, or until a toothpick inserted in the center comes out clean. For around 30 mini cupcakes, bake for about 11-13 minutes, same oven temperature. Allow the cupcakes to cool completely before frosting.

Puree 1/2 cup—2/3 cup blackberries in a small food processor. Push through a fine mesh strainer to rid the seeds. You’ll have a couple Tablespoons of puree.

In a large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the cream cheese and butter together on high speed until smooth and creamy. Add confectioners’ sugar, vanilla, blackberry puree, and salt. Beat on low speed for 30 seconds, then switch to high speed and beat for 2 minutes.

Frost cooled cupcakes. I used Wilton #12 round tip. Garnish with remaining berries.