Preheat oven to 375 degrees F. Line two baking sheets with parchment paper or a silicone mat; set aside.
In the bowl of a stand mixer, fitted with the paddle attachment, cream the butter and sugars until smooth. Mix in the egg and vanilla until incorporated.
In a separate medium bowl, combine the flour, baking powder, baking soda and salt. Give it a quick whisk to combine. With the mixer on low speed, gradually add the flour mixture to the wet ingredients until just combined. Stir in the oats, then the white chocolate chips. Shape 1-tablespoon sized dough balls and place 2 inches apart on the lined baking sheets.
Press (or tuck) about 6 to 8 pomegranate arils into each dough ball and reshape if needed. Bake the cookies for 10 to 12 minutes, until the cookies are just turning golden brown. Remove from the oven and let cool on the baking sheets for two minutes. Transfer to a wire rack to cool completely.