Preheat oven to 325°F (160°C).

In a large bowl, beat egg white until foamy.

Add pecan halves and gently stir to coat.

Combine sugar and brown sugar; add to pecan mixture and stir gently to coat.

Spread pecan mixture into two greased 15x10x1-in. baking pans.

Bake for 18-22 minutes, stirring once halfway through.

Cool completely.

Store in an airtight container.

In a separate large bowl, cream butter, cream cheese, and brown sugar until light and fluffy.

Add eggs, one at a time, beating well after each addition.

Beat in vanilla extract.

Combine flour, baking powder, baking soda, and salt in another bowl.

Add the dry ingredients to the creamed mixture alternately with sour cream, beating well after each addition.

Stir in chopped pecans.

Transfer batter to a greased and floured 10-in. fluted tube pan.

Bake at 325°F (160°C) for 60-70 minutes, or until a toothpick inserted in the center comes out clean.

Cool in pan for 10 minutes before removing to a wire rack to cool completely.

In a small saucepan, combine brown sugar, butter, and milk.

Bring to a boil and cook, stirring constantly, for 1 minute longer.

Remove from heat and stir in confectioners' sugar and vanilla extract until smooth.

Drizzle the glaze over the cooled cake.

Serve with candied pecans (optional).