Start by preheating your oven to 350°F (175°C). While the oven heats up, line two standard baking sheets with parchment paper to prevent sticking and ensure even baking. Set the prepared sheets aside.

In a large mixing bowl, combine the softened unsalted butter, light brown sugar, and granulated white sugar. Beat these together with an electric mixer on medium speed for 1 to 2 minutes, until the mixture becomes light, pale, and wonderfully fluffy. This creaming step is crucial for incorporating air, which contributes to a tender cookie.

Next, add the two room-temperature egg yolks and the vanilla extract to the creamed butter and sugar. Continue mixing for another 1 to 2 minutes, ensuring the mixture becomes even lighter in color and very fluffy. This ensures all the liquid ingredients are well integrated before the dry ingredients go in.

Now, it's time to incorporate the creamy peanut butter. Add the 1/2 cup of peanut butter to the bowl. Mix on a medium speed until it's completely smooth and fully combined with the butter and sugar mixture. Make sure to scrape down the sides of the bowl to ensure everything is evenly mixed and no pockets of unmixed ingredients remain.

In a separate small bowl, whisk together the all-purpose flour, baking soda, baking powder, and salt. Gradually add these dry ingredients to the wet mixture, mixing on low speed just until combined. Be careful not to overmix! The dough will initially seem quite soft, but don't be tempted to add more flour; it will firm up slightly as it rests and cools.

Using a 2-tablespoon capacity cookie scoop, portion the dough into 16 uniform balls. Arrange them on your prepared baking sheets, leaving about two inches between each one to allow for proper spreading during baking. This spacing helps prevent them from merging into one giant cookie.

Bake the cookies for 10 to 11 minutes. For a truly chewy cookie with a soft center, aim for exactly 10 minutes. If you prefer a slightly crispier edge, bake for the full 11 minutes. The edges should appear set, but the centers might still look a little soft and underbaked; this is perfectly normal and desired for chewiness.

Once baked, remove the sheets from the oven and let the cookies cool on the baking sheets for five minutes. This allows them to finish setting up without breaking apart. Then, carefully transfer them to a wire cooling rack to cool completely. Enjoy these delightful Peanut Butter Cookies once they've reached room temperature!