Preheat oven to 350°F. Allowing the oven to fully heat ensures the cookies set quickly and maintain their shape.
Beat the softened butter and allulose until creamy. The mixture should turn pale and fluffy, which helps the dough stay light and promotes even baking.
Add the egg and vanilla; mix well until fully incorporated. The dough may look slightly looser—this is expected and will tighten once the dry ingredients are added.
In another bowl, whisk together the almond flour, oats, cinnamon, baking powder, and salt. This step distributes the spices and leavening evenly so every cookie bakes consistently.
Add the dry mixture into the wet ingredients and mix until combined. The dough should appear thick with visible oats.
Fold in the cranberries gently so they distribute throughout without crushing. Their tartness balances the sweetness of the cookie beautifully.
Chill the dough for 20 minutes for best texture. Chilling helps the cookies hold their shape, preventing excessive spreading.
