Blackberry Lemon Oatmeal Cream Pies

Cookies:

Mix the melted butter and sugars, then whisk in the eggs and vanilla. Fold in the dry ingredients (flour, baking soda, salt, cinnamon), then the oats. 

Let the dough rest for 5 minutes before scooping. Scoop onto a parchment-lined baking sheet, then refrigerate or freeze for at least 15 minutes before baking. 

Bake at 350°F for 9–11 minutes until the edges are set. Cool completely before filling.

Blackberry Compote:

Cook the blackberries, sugar, lemon juice, and salt over medium heat for 8–10 minutes. For a smooth filling, strain out the seeds. Return to the pan, stir in the cornstarch slurry (1 tsp cornstarch + 1 tsp cold water), and cook 1–2 more minutes until thick. Cool completely.

Lemon Vanilla Buttercream:

Beat softened butter, powdered sugar, vanilla, zest of 1 lemon, 1–2 tsp lemon juice, and a pinch of salt until light and fluffy. Add 1–2 tsp heavy cream if needed.

Assemble:

Pipe a ring of buttercream around one cookie, spoon 1–2 teaspoons of blackberry compote into the center, top with another cookie, and enjoy.