Preheat your oven to 350°F (175°C). Line your baking sheet with parchment paper to prevent sticking and ensure even baking.
In a large mixing bowl, whisk together the almond, quick cooking rolled oats, unbleached all-purpose flour, and salt until well combined. Set aside.
In another bowl, use an electric mixer to cream together the softened unsalted butter, solid vegetable shortening, and brown sugar until the mixture is light and fluffy (about 2-3 minutes).
Add the egg yolk and vanilla extract to the creamed butter and sugar mixture. Beat until fully incorporated.
Gradually add the dry ingredients to the wet mixture, mixing until just combined. Be careful not to overmix; you want a thick dough.
Using a cookie scoop or tablespoon, drop rounded balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Using your thumb or the back of a spoon, gently press down in the center of each cookie to create a small well. This is where your delicious Forest Berries jam will go!
Spoon about 1/2 teaspoon of Forest Berries jam into each thumbprint, ensuring it’s nestled securely in the center.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden. The centers may look soft, but they will firm up as they cool.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. Enjoy the warm, fruity goodness!