For the crepes, whisk together the plant-based milk and apple cider vinegar in a mixing bowl. Let sit for 5 minutes. Add the olive oil and sugar, then whisk to combine. In a separate bowl, whisk the all-purpose flour, cornstarch, and sea salt. Gradually add the dry ingredients to the wet ingredients, whisking until smooth. Let the batter rest for 10 minutes.

Heat a non-stick skillet over medium heat and lightly coat with vegan butter or oil. Pour a small amount of batter into the skillet, swirling to spread it into a thin, even layer. Cook until the edges lift slightly and the bottom is golden brown, 1-2 minutes.

Flip and cook for another 30-60 seconds. Transfer to a plate and repeat with the remaining batter, adding more butter or oil as needed.

For the kasha and fried onion filling, heat 1 tablespoon of olive oil in a pan over medium heat. Add the minced garlic and cook for 30 seconds until fragrant. Stir in the kasha, salt, black pepper, and thyme. Toast for 1 minute, stirring frequently. Pour in 1 ⅓ cups of water and bring to a boil. Reduce to a simmer, cover, and cook for 10-12 minutes, until the liquid is absorbed and the kasha is tender. Remove from heat and let rest for 5 minutes before fluffing with a fork.

In a separate pan, heat the remaining 2 tablespoons of olive oil over medium heat. Add the chopped onions and cook, stirring occasionally, until deeply golden brown, 15-20 minutes. Stir the caramelized onions into the cooked kasha.

For the sweet cheese filling, pour boiling water over the cashews in a heat-proof bowl and let them soak for at least 20 minutes. Drain and rinse the cashews.

Blend the tofu, drained cashews, agave nectar, plant-based yogurt, rice vinegar, white miso paste, vanilla extract, and salt in a food processor until completely smooth, scraping down the sides as needed.

To assemble, fill each crepe with the desired amount of kasha and fried onion filling or sweet cheese filling. Fold or roll the crepes and serve immediately with apple sauce and vegan sour cream. Optionally you can pan fry the stuffed blintzes in vegan butter on a couple of sides before serving.