Place unsalted butter in the bowl of a stand mixer (or large bowl if using an electric hand mixer). Arrange 2 racks to divide the oven into thirds and heat the oven to 350°F.

Meanwhile, line 2 baking sheets with parchment paper. Trim and finely chop strawberries until you have 1 cup.

Add 1 cup packed light brown sugar to the bowl of butter. Beat with the paddle attachment on medium speed until fluffy, about 3-4 minutes.

Add the egg and 1 teaspoon vanilla extract and beat until combined, about 2-3 minutes.

Place oats, 1 cup all-purpose flour, 1/2 teaspoon kosher salt, 1/2 teaspoon baking soda, and 1/4 teaspoon baking powder in a medium bowl and stir to combine. With a rubber spatula, add the flour mixture to the butter mixture and fold gently until just combined.

Add the strawberries and white chocolate chips to the batter and fold in with rubber spatula until just combined.

Divide the dough into 16 to 18 (about 3 scant tablespoon) portions. Form into balls and place on the baking sheets, spacing them even apart. You can also use a cookie scoop for this.

Lightly press down on each dough ball until about 2 inches wide. Bake for 8 minutes. Rotate the baking sheets from top to bottom and front to back halfway through. Continue to bake until golden-brown and no longer shiny, about 5-7 minutes more. Let cool on the baking sheets for 5 minutes. Transfer the cookies to wire racks and let cool completely. ENJOY!