Preheat oven to 350°F. Grease an 8x8-inch pan and line with parchment paper. Set aside.

Place the oats in a food processor and pulse until coarsely ground. Set aside.

In a large bowl, whisk together the butter and brown sugar until slightly lightened in color. Add in the syrup, egg, and vanilla, and whisk until thoroughly combined.

Using a spatula, stir in the ground oats, flour, and salt until just combined. Fold in the walnuts and white chocolate chips. Pour batter into the prepared pan, spreading evenly.

Bake for 30-35 minutes, until the edges are golden and the center is set. (I tend to err on the side of under-baked with blondies, as I feel people prefer those to an over-baked blondie.)

Allow to cool in the pan, then use the parchment paper to lift the blondies out the pan. Cut into pieces and serve. Store in an airtight container for up to 4 days.

In a medium bowl, beat together the butter, cream cheese and powdered sugar and salt. Add the maple syrup and vanilla and beat until smooth. Store in the refrigerator until ready to use.

When ready to serve, heat a small skillet over medium heat until hot.

Microwave the sauce in 15-second intervals until pourable.

Place a blondie in the hot skillet; top with a scoop of vanilla ice cream, drizzle with the maple butter sauce, and serve.