Preheat oven to 350F.

Cookies:

1. Cream the butter, sugar, and molasses until light and fluffy. Approximately 2-3 minutes.Stop and scrape the bowl.
2. Combine the eggs and vanilla bean paste.
3. Add the egg mixture to the creamed butter mixture. Stop and scrape the bowl.
4. Meanwhile, in a separate bowl combine the oats, all purpose flour, baking soda, salt, and cinnamon.
5. Add the dry ingredients and mix just until incorporated. Stop and scrape the bowl.
6. Line a sheet pan with parchment paper. Using the #70 ice cream scoop or a tablespoon, place mounds of dough onto the sheet pan. Make sure to space them apart because the cookies will spread.
7. Bake for approximately 8- 10 minutes.
8. Allow cookies to cool completely on the baking sheet pan.

Apple Filling:

1. Peel and small dice the apples
2. Combine the diced apples, brown sugar, cinnamon, nutmeg, and cornstarch.
3. Melt the butter in a medium saucepan then add the apples.
4. Cook for approximately five minutes. Stir occasionally. Apples should soften but still have a slight crunch.
5. Remove from heat and allow to cool uncovered at room temperature

Swiss Buttercream:

1. Heat a small pot of water over medium-low heat until it steams. In the bowl of a stand mixer, combine the egg whites and granulated sugar. Whisk occasionally and heat until the sugar has dissolved completely. Do not overheat.
2. Remove from heat and place the bowl back onto the stand mixer.
3. Fit stand mixer with whisk attachment and whisk on high speed.
4. Whip on high speed until it holds medium stiff peaks. Continue beating until the mixture is fluffy and cooled, about 5 minutes.
5. With the mixture on medium-low speed, gradually add the softened butter, beating well after each addition. Stop and scrape the bowl.
6. Whip on medium speed until smooth for about 4 minutes. Add vanilla bean paste. Stop and scrape the bowl.