In a medium bowl, add ricotta, lemon zest, oil, and salt. Use a whisk or electric beater to whisk/beat until smooth. For an ultra creamy ricotta, whisk in a splash of heavy cream.
For vegan ricotta, add soaked seeds, lemon, oil, and salt to a high-speed blender and blend until smooth, scraping down the sides as needed. Taste and add more lemon or salt, if needed.
Top each toast generously with the whipped ricotta and place the avocado slices on top, pressing gently to adhere. Top everything with a drizzle of good olive oil, more lemon zest, flaky salt, and black pepper.