Preheat oven to 350 degrees Fahrenheit.
If grinding your own walnuts, spread the walnuts on a cookie sheet lined with parchment paper, and bake for 4 minutes. Toss the walnuts and bake for 4 more minutes. Let them cool completely before grinding them in a food processor, blender of crushing with a meat mallet. Try not to grind so long that it turns into a paste or that it turns into a powder (Depending on the method you're using). If using a meat mallet, place the cooled nuts in a ziplock back, place between tea towels, and crush.
Cream the butter and sugars together in the bowl of an electric mixer on low speed. (Use the paddle attachment). Mix until thoroughly incorporated - for about one minute. Scrape down the sides of the bowl with a plastic spatula and mix again for a few seconds more. Over mixing the butter and sugar in this step will cause too much air to be incorporated into the dough. If you'd like a light and fluffy cookie, that's ideal, however the dough will spread more during baking; not ideal if you'd like the cookie to hold its shape.
Add eggs slowly and mix. Scrape down the bowl with your spatula at least once and mix again. Add maple syrup and maple extract, mix, and add walnuts or walnut flour. Mix until just incorporated.
Add the flour in 2 or 3 stages to the bowl and mix on low speed for about 30 seconds to 1 minute, and observe the dough mixing. When it starts to come together and the dough clumps around the paddle attachment and peels away from the sides of the mixer, it should be the right texture. I used 6 cups of flour because my walnut mixture was moist, you may need to use less or even more. You can also test the dough by pinching it between your thumb and index finger. If it’s soft but not sticky, it’s just right. If it’s too sticky when you pinch it between your fingers, add flour, ¼ cup at a time, and mix until you’re happy with the texture.
Roll the dough out between 2 large pieces of parchment paper. Place on a baking sheet and into the fridge or freezer for a minimum of 1 hour.
Cut out cookie shapes. Place on parchment paper-lined baking sheets. Re-roll scraps and repeat. If your dough gets too soft to work with, place in the fridge or freezer periodically to firm up again.
Once all cut out, put cookie dough shapes back into the fridge or freezer for 10 minutes to 1 hour to chill again. They will then hold their shape better when baked.
Preheat your oven to 350°F or 176°C.
Bake cookies for 8-12 minutes or until the edges become golden brown. The baking time will depend on the size of your cookie.
Let cookies cool to room temperature and decorate if you like! If you’re new to decorating cookies, I have basic cookie decorating tutorials with everything you’ll need to know to begin on my blog. Have fun!