Preheat oven to 350 degrees Fahrenheit. Butter a 10-inch cake pan, baking pan or cast-iron skillet.

In a food processor, grind ½ cup whole walnuts until close to finely ground. You may have a little more than half a cup after grinding. Transfer to a medium bowl, add almond flour, arrowroot starch, baking powder, and salt.

In a large bowl, add butter, and beat with an electric mixer until light and fluffy. Add honey to the butter, beat until combined. Add eggs, one at a time, until well blended. Beat in vanilla extract. Add flour mixture in until combined. Set aside.

To make streusel topping, in a small bowl combine chopped walnuts, almond flour, coconut sugar, and cinnamon. Cut cold butter in pieces and add to mixture blending with a pastry blender or using two knives until butter resembles small pebbles.

Give batter another stir, then pour into prepared pan. Lay pear slices on top of batter. Sprinkle pumpkin pie spice blend over pears. Cover pears evenly with streusel topping.

Bake for about 50 minutes or until toothpick comes out clean. Cool buckle on wire rack.

To make cinnamon-whiskey whip, scoop waxy solid out of can of coconut milk into a medium bowl, stopping when you hit liquid. With electric mixer on medium-low, beat until coconut milk starts to form soft peaks. Add honey, cinnamon and vanilla extract, beating until combined. Add whiskey, continuing to mix until combined.

Serve buckle warm or at room temperature with a dollop of whip.