How to Make It
Preheat oven to 375°F.
Using a paring knife, or an apple corer, cut a circle around the stem three-quarters of the way down through each apple. Use a spoon to scoop out the filling. Discard the core and chop the remaining scooped-out apple. Reserve.
Melt butter in a small saucepan. Remove from heat and stir in maple syrup. Reserve ¼ cup mixture for drizzling over baked apples. Brush remaining butter mixture on the inside of the apples.
In a medium saucepan, combine the remaining water, oats, chopped apple chunks, cinnamon, nutmeg and salt, and bring to a boil over medium-high heat. Reduce to a simmer and cook for a 6 to 8 minutes or until most of the liquid is absorbed. Stir in the heavy cream, brown sugar, and ½ cup of chopped walnuts. Remove from heat.
Evenly divide oatmeal mixture between the apples. Top with remaining walnuts and bake for 15 minutes. Drizzle with remaining butter mixture before serving.