• Preheat the oven to 400°F (200°C). Line a 12-cup muffin pan with large muffin liners.
• Whisk flour, sugar and nutmeg together in a large bowl. Add the walnuts; stir to combined.
• Whisk together the eggs, butter, buttermilk, zest and vanilla in a medium bowl until well combined. Add to the flour mixture and stir until combined. Spoon the mixture into the muffin liners – an ice cream scoop works well for this. Bake on the top shelf in the preheated oven for 25 minutes or until a skewer inserted into the center of a muffin comes out clean.
• Let stand in the pan for 5 minutes before turning out onto a wire rack.

To make the lemon glaze:

• Melt the butter in a small saucepan over medium heat. Add the lemon juice and sugar; whisk or stir until the glaze is smooth.
• Drizzle the glaze over the warm muffins. Let stand until the glaze is set. Makes 12.