Do step 1 of the glaze first so the strawberries can be macerating while preparing cake.

Peel and dice potato and place in a saucepan. Cover with 1-inch of water. Do not add salt to the water. Bring to a boil and simmer until tender, about 20 minutes. Drain water. Mash potato until smooth (no lumps!). Allow to cool to room temperature.

Preheat oven to 350 degrees F. Lightly grease a bundt cake pan and dust pan with cocoa powder.

Whisk together flour, cocoa powder, baking soda, and salt in a medium bowl.

Beat butter and sugar in a large bowl until light and fluffy. Add eggs and vanilla, beating well after each addition. Add 1 cup mashed potato and mix to combine. (Reserve any remaining potato for another use if desired).

Add flour mixture, alternately with buttermilk, beginning and ending with flour mixture. Mix until just combined after each addition (do not over-mix).

Transfer batter to prepared pan, spreading evenly in the pan.

Bake for 50 to 55 minutes or until a toothpick or cake tester inserted in the center comes out clean.

Cool cake in the pan for 10 minutes then remove cake from pan and cool completely on a wire rack.

Stir together strawberries and granulated sugar in a bowl. Chill for at least 2 hours.

Place strawberries and juice in a blender. Blend until completely puréed. Strain through a fine mesh sieve to remove as many seeds as possible. You may have to push purée through the sieve using a spoon or rubber spatula.

Stir together confectioners sugar, butter, vanilla, salt, and 3 tablespoons strawberry purée in a medium bowl.

Add more strawberry purée, one teaspoon at a time, until desired consistency is reached. Save any remaining purée for another use (great to use for cocktails or smoothies).

Drizzle or spoon glaze on top of cake on a wire rack placed over parchment paper or aluminum foil (to catch overflow if any).

Transfer glazed cake to a serving platter or cake dish.