Step 1

For the cookies: In a medium frying pan over medium heat, toast the oats while tossing frequently until lightly browned and aromatic, 5 to 6 minutes. Transfer the oats to a bowl to fully cool.

Step 2

In a medium bowl, whisk to combine the flour, cinnamon, baking soda and salt.

Step 3

In a separate medium bowl, cream the butter and miso paste together with a flexible spatula until smooth. Add the granulated and brown sugars and mix until smooth. Add the egg and vanilla and mix until very smooth, pale and slightly airy. Add the dry ingredients and mix until a few dry streaks remain, then fold in the oats until well combined. Cover the bowl and chill in the fridge to slightly firm up, about 30 minutes.

Step 4

Scoop 1 1/2-tablespoon portions of dough and roll each portion into a ball. Refrigerate the balls for an additional 30 minutes to 1 hour.

Step 5

Preheat the oven to 350 degrees F and line 2 baking sheets with parchment paper.

Step 6

Arrange 6 of the dough balls on each baking sheet, allowing at least 3 inches between the cookies (they spread a lot in the oven). Keep the remaining dough balls refrigerated.

Step 7

Bake until the cookies are deeply golden brown and crispy around the edges, 9 to 11 minutes. Set the sheets on a wire rack and allow the cookies to fully cool on the sheets (they will be soft at first but will crisp up as they cool). Remove the cookies to the wire rack. Arrange the remaining dough balls on one of the cooled baking sheets. Bake and cool the last batch.

Step 8

For the glaze: Once the cookies are cool, make the glaze. In a small bowl, whisk to combine the confectioners' sugar, milk and vanilla. Test the consistency by drizzling it over a cookie. If the glaze is too thin and running off the cookie, add a little more confectioners' sugar; if the glaze is too thick, add a tiny bit more milk. Drizzle the glaze over the cookies and allow it to set for a few minutes. Serve the cookies immediately or store in an airtight container for up to a week.