Warm the milk to 110F and combine with granulated sugar and instant yeast in a bowl. Let sit for 5-10 minutes until foamy.

In a separate bowl, mix together the melted butter, egg, and egg yolk.

Combine the flour and salt in a mixing bowl. Gradually add the milk mixture and butter mixture. Mix until a dough forms.

Knead the dough on a floured surface until smooth, then let it rise for 1 hour or until doubled in size.

While the dough is rising, prepare the peach filling by combining diced peaches, brown sugar, cinnamon, cornstarch, water, and vanilla in a saucepan. Cook over medium heat until thickened, about 5-10 minutes.

Roll out the dough on a floured surface to about 1/2 inch thick. Cut out donut shapes.

Heat avocado oil in a deep skillet. Fry the donuts until golden brown on both sides, about 3-4 minutes per side. Drain on paper towels.

For the glaze, brown the butter in a saucepan, then mix with powdered sugar, maple syrup, milk, and vanilla. Add a pinch of salt.

Dip the cooled donuts in the glaze and serve.