Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

Combine rolled oats, all-purpose flour, baking powder, salt, and optional black pepper in a large mixing bowl.

Cream unsalted butter and granulated sugar together until light and fluffy, about 3-5 minutes.

Chop the fresh rosemary and mix into the butter-sugar mixture until evenly distributed.

Gradually add the dry mixture to the butter and rosemary blend, mixing gently until just combined.

Slowly add water into the dough, one tablespoon at a time, until a soft but not sticky consistency is reached.

Shape the dough into rounds about ¼ inch thick and place them on the lined baking sheet.

Bake for 20-25 minutes or until the edges are golden brown.

Cool on the baking sheet for about 10 minutes before transferring to a wire rack.