Preheat the oven to 350 F. Line 2 cookie sheets with parchment paper.
Add old-fashioned oats, all-purpose flour, baking soda, baking powder, and fine sea salt to small bowl. Whisk to combine. Set aside.
Add unsalted butter, light brown sugar, and granulated sugar to stand mixer. Beat on medium for 2 minutes, or until light and fluffy.
Add egg, whole milk, and vanilla bean paste to sugar mixture. Beat on low until fully incorporated.
Remove bowl from stand mixture. Fold in oats mixture, pecans and chocolate. Do not over mix.
Scoop and drop cookie dough on prepared cookie sheets using a 2-ounce cookie scoop or 1/2-cup measuring cup. Do not press down cookies.
Bake 14 to 16 minutes. Cookies should be golden along the edges and set in the center.
Remove cookie sheet from oven and place on wire racks to cool for several minutes. Remove cookies from cookie sheets to cool completely.
Store in an airtight container at room temperature for up to 3 days.