Preheat oven to 350 degrees. Line 2 baking sheets with parchment paper.
In a bowl, combine butter, brown sugar, granulated sugar and corn syrup and stir until blended. Stir in oats, mixing well.
To form the crisps, drop the oat mixture by tablespoonfuls onto the prepared baking sheets, spacing them about 2 1/2 inches apart. Bake, rotating the baking sheets 180 degrees at the midway point, until golden brown and bubbly, about 15 minutes. Let cool for 5 minutes on the baking sheets. Then, using a metal spatula, transfer the crisps to a large flat plate to cool.
To serve, divide blueberries and crème fraîche among individual bowls and place 2 oat crisps alongside or on top of each serving.
Planning ahead: The oat crisps may be made a day in advance. Store in an airtight container at room temperature.
Classic Stars Desserts (Chronicle Books 2007)