Preheat oven to 350°F (175°C). Line baking sheets with silicone liners or parchment paper.
Whisk together the flour, baking powder, salt, and cinnamon. Stir in the oats. Set aside.
Using an electric mixer on medium speed, beat the butter and brown sugar until light and fluffy. Add the eggs, one at a time, mixing well after each addition. Mix in the vanilla.
Reduce mixer speed to low. Gradually add the flour mixture, mixing just until combined. Stir in the cherries and white chocolate.
Using 3 tablespoons of dough at a time, drop the dough onto the prepared pans, leaving about 2 inches between cookies. Flatten each cookie slightly.
Bake 18 to 22 minutes, or until the cookies are lightly browned.