Hobnobs, a type of classic British biscuits, are essentially crunchy oat cookies with a buttery caramel flavor. The chocolate bottoms are optional, and these crisp cookies are delicious either way. They're quick and easy to whip up with simple ingredients!
Preheat the oven to 350F. Line 2 large baking trays with parchment paper.
Pulse the oats 3 times (for 1 second each pulse) in a food processor (don’t overdo it!).
Melt together the butter and golden syrup in a large microwave-safe bowl or in a double boiler, whisking to combine. Whisk in the golden caster sugar until the mixture is thick and glossy (if it’s not turning thick and glossy, heat it briefly in microwave or double boiler after adding the sugar, but don’t overdo it). Whisk in the vanilla.
Add the pulsed oats, flour, baking powder, baking soda, salt, and cinnamon (if using) to the bowl with the butter mixture. Stir to combine (the cookie dough will seem a bit gritty and dense; which is normal).
Use a 1.5-tablespoon scoop to measure out the dough (slightly compacting the dough into the scoop when you measure), and roll each into a ball (compact the dough with your hands as you roll it so it forms a nice round shape).
Arrange the dough balls spaced evenly apart on the baking trays. Slightly flatten each dough ball. Bake until the cookies are golden to your liking, about 14 to 16 minutes.
Let the cookies cool completely (about 20 minutes). Once cool, melt the chocolate and spread it evenly across the bottom of each cookie.
Let the chocolate set before serving.
Notes
Golden Syrup Substitute: You can easily find golden syrup on Amazon, at local British markets, or in the international foods aisle at your local grocery store. However, in a pinch you can substitute golden syrup 1:1 for maple syrup, honey, or simple syrup in this recipe.
Golden Caster Sugar Substitute: If you don't have golden caster sugar, then regular caster sugar (aka "superfine sugar") will also work well. And if you don't have regular caster sugar, you can pulse regular granulated white sugar in a food processor or blender a few times until it's finely ground. But don't go too long or you'll end up with powdered sugar!
For More Perfectly Rounded Cookies: As soon as the cookies are out of the oven, place a 4-inch round ring (you can use a bowl, large glass, cookie cutter, etc.) around 1 cookie at a time. Gently roll the ring around so that the sides of the cookie flatten against the ring.
Storage: Once the chocolate is set, you can layer the cookies in a cookie tin between pieces of wax paper or parchment paper. (If you skip the chocolate bottoms, you don't need to layer them between pieces of paper.) Store them like this at room temperature for up to 3 days, in the fridge for up to 1 week, or in the freeze for up to 3 months.