Add white chocolate chips to a large microwave-safe mixing bowl. Heat chocolate in 15-30 second intervals, stirring in between with a spatula until chocolate is completely melted and smooth. You can also melt the chocolate on the stove using the double boiler method.
Using a whisk, add in lemon juice and whisk until lemon juice is fully incorporated and the mixture becomes uniform in color and smooth.
Switch to a spatula and stir in the zest and quick oats until they are evenly mixed in. The batter should be thick.
Use a 1 tbsp cookie scoop to scoop up cookie batter and place onto the prepared cookie sheet, spacing cookies 2 inches apart. The batter may spread out a little but it should not spread much. Use the back of a spoon to flatten cookies into a thick round disk (about 1/4 inch thick), smoothing edges and top as needed. You can also use your fingers to help shape the edges of the cookies. Cookies will not change shape so shape them to how you would like your final cookies to look like.
If desired, garnish the top of cookies with additional zest. It will add more lemon flavor and add some color to the cookies. Place cookies into fridge to set. This can take about 30 minutes to one hour. When cookies are set they should feel firm and you should be able to peel the cookies off of the parchment paper. Let cookies sit at room temperature for about 10-15 minutes before eating. You can also eat them straight out of the fridge but the chocolate will be a little more firm when it's cold. Store uneaten cookies in an airtight container in the fridge or freezer.
Notes
You will need approximately 1 large lemon for this recipe. You likely won't need all of the juice and zest it produces.
To measure the lemon zest, make sure your zest is mostly dry and then loosely add it to the measuring spoon. Do not pack it in.
When measuring out the lemon juice, make sure you strain out any pulp so you have 2 full tbsp of just lemon juice.
There is some flexibility with the amount of quick oats that can be added. If you prefer a sweeter cookie, you can reduce the oats by 2 tbsp.
If you want more oat flavor in your cookies, you can increase the quick oats by 2 tbsp.
You can make the cookies larger (or smaller) if you wish. I made them smaller than your average cookie because they are very rich.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.