Preheat the oven to 350 degrees.
Line two baking sheets with parchment paper.
Place oats in the bowl of a food processor. Pulse lightly until the flakes of oatmeal are more like a powder.
In a large bowl, whisk together the flour and pulsed oats.
Add the baking soda, cinnamon, and nutmeg. Set aside the dry ingredients.
Add the softened butter to the bowl of a stand mixer fitted with the paddle attachment. You can use a hand mixer if necessary and even a wooden spoon will do in a pinch.
Add the granulated and brown sugar to the butter and mix until light and fluffy, about 2 minutes.
Add the eggs and mix until combined.
Add the vanilla extract and the molasses. Mix until combined.
Add the flour mixture to the wet ingredients. Mix until just combined. Be sure to scrape down the sides and up from the bottom of the bowl with a spatula to ensure everything is incorporated. Remember not to over mix the dough to avoid making a tough cookie.
Using a cookie scoop, scoop out the cookie dough and place on the prepared baking sheets. Leave about 2 inches between the cookies for spreading.
Flatten the cookie dough balls slightly with the bottom of a glass.
Bake cookies for approximately 10-12 minutes or until golden brown. If using more than one cookie sheet, switch their positions midway through the baking time.
Let the baked cookies cool on the tray for 4 minutes, then remove to a wire rack to complete cooling. You must wait until the cookies are completely cool before icing.
Add the confectioners sugar and heavy cream to a small bowl, whisking to combine. You can make the icing a little thinner by adding more cream if necessary.
Prepare a dipping station (see Tips & Tricks).
Dip the tops of the cookies in the icing mixture, allowing the excess icing to run back into the bowl.
Let the icing dry before serving.