Dissolve yeast in warm water. Let proof for a few minutes. Put in mixing bowl.

Add soy milk (warmed in a microwave for two minutes), sugar, oil, eggs, and half the flour, and beat until smooth.

Add salt and enough remaining flour to form a soft dough. Knead for five to six minutes.

Place in a greased bowl or bag, turning once to grease the top. Cover and let rise in a warm place until doubled, about 45 minutes.

Meanwhile mix light brown sugar and vanilla sugar for the filling in a small bowl.

Punch dough down and divide in half. Roll each half into a large rectangle about 14 x 9 inches (35 x 22.5 centimeters).

Spread with half the peanut butter and sprinkle with half the sugar mixture.

Roll dough up, jelly-roll style, starting with the longer side. Pinch edges to seal. Cut each (slightly on the diagonal for prettier slices) into 18 slices. Place, cut-side down, in two greased baking pans. Cover and let rise until doubled, about one hour.

Fifteen minutes before end, preheat oven to 375 degrees Fahrenheit (190 degrees Celsius). Bake for 20–25 minutes or until light brown.

Combine glaze ingredients in a small bowl. Drizzle over warm buns or pour in the center of each. Cool.