Preheat your oven to 350?F (177?C). Cover several baking sheets with parchment paper.

In an electric stand mixer fitted with the paddle attachment, add the peanut butter, butter, brown sugar, granulated sugar, and vanilla. Mix on medium for about 4 to 5 minutes, or until smooth and well blended.

Add the eggs one at a time, ensuring each is fully blended before adding the next. Scrape down the sides and bottom of the bowl to incorporate everything.

Add the baking powder, baking soda, and salt, and mix for 1 minute more. Add the flour and mix for about 20 seconds or until just combined.

Add 1/2 cup granulated sugar to a shallow bowl. Use a cookie scoop to portion 2 tablespoons of cookie dough and drop the dough into the bowl of granulated sugar. Gently cover in sugar and set on the prepared baking sheet, leaving 1? inches (4 cm) between each dough ball.

Bake one sheet at a time for 12 to 13 minutes in the center of the oven. The cookies will be very soft when you get them out of the oven. Tap the baking sheet on the counter to gently deflate the cookies and sprinkle with sea salt flakes, if using.

Let them cool for 20 minutes on the baking sheet before transferring to a cooling rack.