Heat oven to 350 degrees F.
Using freestanding electric mixer fitted with the whisk attachment, in a medium-size bowl, beat together on low speed the flour, baking powder, sugar and oats until well blended. In a medium-size bowl, stir together the heavy cream, corn syrup, melted butter and vanilla until well blended. Add to flour mixture; on low speed, beat just until the ingredients are combined.
Let the cookie batter stand in the bowl at room temperature for about 15 minutes.
Drop the cookie batter in heaping teaspoons onto nonstick foil-lined baking sheets, spacing the mounds out evenly and keeping in mind that there should be enough room for the mounds to spread out flat into cookies. You can fit about 6 cookies on a 17 x 14-inch baking sheet.
Bake the cookies in 350 degree oven until golden brown, 8 to 10 minutes. Transfer baking sheets to wire racks; let cookies cool 2 to 3 minutes on the baking sheet. Then, using metal spatula, carefully transfer cookies to wire racks; let the cookies cool completely. To store, layer the cookies between sheets of wax paper in airtight container at room temperature for up to 3 days. Makes 24 cookies.