Set your oven to 350°F (175°C).

Place the slices of bread on a rimmed baking sheet. Do not butter or grease. Toast in the oven for 4-6 minutes, or until the bread is golden brown and crispy. Keep a close eye on it to prevent burning.

While the bread toasts, peel and pit the avocado. Use the back of a fork to gently mash the avocado to your desired consistency. Season with a pinch of salt. Set aside.

Place 2 teaspoons of olive oil in a large skillet and set over low heat for 5 minutes. While the pan heats, crack each egg into two small bowls. Season with salt and pepper.

Increase the heat to medium-high until the oil looks shimmery. Add the cold butter to the skillet and quickly swirl to coat the pan.

Pour one bowl of egg onto one side of the pan and the second bowl onto the other side. Cover the skillet and cook for exactly 1 minute.

For runny yolks with barely opaque whites, remove the skillet from the heat and let it stand, covered, for 15 to 45 seconds. For soft but set yolks, let it stand for 45 to 60 seconds, and for medium-set yolks, let it stand for about 2 minutes. Timing is key here, so set a timer if needed.

Spread the mashed avocado evenly over each slice of toasted bread.

Top with a fried egg from the skillet. Serve immediately.