These Hobnobs are a classic British biscuit. They're full of oats & have a rich flavor with a caramel-y, buttery sweetness. They go splendidly with a cup of tea!
Preheat the oven to 300 degrees Fahrenheit. Line 2 rimmed cookie sheets with parchment paper.
In a food processor, pulse 1/2 cup of the quick cooking oats until they are closer in texture to oat flour, but not completely broken down. This will probably be around 7-10 pulses. In a medium mixing bowl, whisk together the processed oats, the other 1/2 cup of oats, all-purpose flour, whole wheat flour, baking soda, and kosher salt. Set aside.
In a large mixing bowl, cream the butter and sugar on medium-high speed with an electric hand mixer until lighter in color and fluffy, scraping down the sides of the bowl as needed. Add the golden syrup and milk and mix until incorporated. Using a wooden spoon or a heavy-duty rubber spatula, fold the dry ingredients into the wet ingredients. It will take a bit of folding to come together. It will look really dry and crumbly but keep folding and it will come together!
Once it's combined (there may be a few stray crumbs in the bowl & that's fine!) scoop the cookie dough. I use a medium cookie scoop to portion the dough, but you could also use heaping tablespoon. As you portion the dough, roll each piece quickly into a ball and place on the prepared cookie sheet, leaving about 2 inches of space between the cookies. Once you've filled one cookie sheet with ten cookies, lightly flatten the cookies with your fingers until they are each about 1 1/2 inches in diameter. The edges might split a little as you do this because it's a dry dough. That's ok. You can press the edges back together if you want or just leave it if you can't be bothered.
Place the first tray of cookies in the oven and bake for 18-22 minutes, rotating halfway through baking. Allow to cool on the tray for five minutes, then remove cookies to a cooling rack and cool completely.