Right. So I missed Valentines by about two months with these. Certainly they would have been really cute then! But as far as I know there isn't a rule against eating red hots in April so I just went with it on a day that I had time to commit to multi-step cookies.

I give the oatmeal cookies 3 thumbs up. They are soft and buttery ... just how I like them. They did spread more than I anticipated but frankly that's a frequent problem in my kitchen. (Does anybody know if airbake pans tend to cause more spreading?)
And the buttercream is well, frosting, and frosting is my favorite. As I was making it I kept feeling like the red hot flavor was being overwhelmed by the buttery, sugaryness and I was a bit disappointed. But I found that after the flavors had time to meld and it was slathered between the cookies layers it came out in just the right amount!

Oatmeal Sandwich Cookies with Cinnamon Red Hot Buttercream
Recipe taken from Kitchen Treaty
1 cup (2 sticks) unsalted butter, room temperature
¾ cup granulated sugar
¾ cup packed brown sugar
2 large eggs
1 teaspoon vanilla extract
¾ cup whole-wheat flour (can substitute all-purpose flour)
½ cup all-purpose flour
1 teaspoon baking soda
½ teaspoon salt
½ teaspoon ground cinnamon
3 cups rolled oats (quick-cooking are fine)
½ cup cinnamon red hots candies, divided
¼ cup water
2 sticks (1 cup) unsalted butter, room temperature
2 cups powdered sugar
Pinch salt (I added way more than a pinch but I like sweet things to be nicely salty)
Preheat oven to 375 degrees Fahrenheit.
In the large bowl of a stand mixer affixed with the paddle attachment or in a large bowl using a hand mixer, beat the butter, granulated sugar, and brown sugar until fluffy, about two to three minutes.
Add the eggs one at a time, beating well after each addition.
Add the vanilla extract and mix well.
Place a sifter over the bowl and sift in the flour, baking soda, salt, and cinnamon. Add the oats. Mix just until blended.
Place rounded tablespoonfuls of dough onto a nonstick, ungreased cookie sheet (or line the cookie sheet with a silpat).
Bake for about 8 minutes, until the cookies are set and the edges begin to brown.
Remove from oven and let cool on the cookie sheet for about five minutes, then transfer to a wire rack to cool completely.
In a very small saucepan, add ¼ cup cinnamon red hot candies and ¼ cup water. Stir frequently over low heat until candies are dissolved, about 10 minutes, and remove from heat. Cool to room temperature.
Using a food processor, crush the remaining ¼ cup cinnamon red hot candies until pulverized. Set aside.
In a stand mixer affixed with the paddle attachment, beat the butter at medium speed until pale and fluffy, about one minute.
Reduce the mixer speed to low and slowly add the powdered sugar ½ cup at a time until each addition is well-incorporated. Increase speed to medium and beat for about a minute, scraping down the sides if necessary, until light and fluffy.
Reduce the heat to low and slowly drizzle in the cinnamon red hot syrup. Add the pulverized candies and the pinch of salt and mix, scraping down the sides of the bowl as needed, until well-combined.
Note: I like to use a pastry bag or a Ziploc bag with a frosting tip to make quick work of filling sandwich cookies, but you can use a knife, too.
Turn half of the cookies upside down and add about 2 – 3 tablespoons of frosting to each upside-down cookie by simply squeezing a generous circle of icing from your pastry bag or Ziploc bag, or spread with a knife. Top with the second cookie.
Cookies will keep in an airtight container at room temperature for 2 – 3 days.