Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper, if using.
In a mixing bowl, cream together the softened butter and 1 cup of powdered sugar until light and fluffy. This should take about 3-4 minutes with an electric mixer.
Beat in the vanilla extract, mixing well to combine.
In another bowl, whisk together the all-purpose flour, almond flour, and salt.
Gradually add the dry ingredients to the butter mixture, mixing until just combined.
Scoop a tablespoon of cookie dough and flatten it slightly in your palm. Place a small teaspoon of raspberry jam in the center, then fold the dough over to seal the jam inside. Shape it into a ball and place it on the prepared baking sheet. Repeat with the remaining dough.
Once all cookies are formed, sprinkle the tops with sliced almonds.
Bake in the preheated oven for 15-20 minutes or until the edges are lightly golden.
Allow cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack.
Once cooled, dust with additional powdered sugar before serving.