Preheat oven to 350°F (175°C). Grease 9 x 13” pan.
In a large bowl, stir together 3/4 cup sugar, baking soda, salt and 2 cups flour. Stir in the eggs and yogurt. Mix until smooth. The batter will be very thick but keep mixing until all incorporated. Fold in the rhubarb, you may need to use your hands to thoroughly mix. Spoon into the prepared dish and spread evenly.
In a small bowl combine the sugar, flour and cinnamon then blend in the butter to form a crumbly mixture. Sprinkle over the cake evenly and bake.
Bake between 45 to 50 minutes.