In a small saucepan, combine the sugar with 2 cups water over medium-high heat and cook, stirring occasionally, until the sugar dissolves, about 8 minutes. Remove the pan from the heat and let the syrup cool.
Place the rice flour in the bowl of a stand mixer fitted with a paddle. With the motor running on medium-low speed, slowly drizzle in the syrup and mix until smooth. Pour in 2 tablespoons oil and the almond extract and continue beating until the batter is evenly combined.
Grease a 9-inch cake pan with oil then pour in the batter. Set a bamboo steamer over 1 inch of simmering water in a wok, and place the cake pan in the steamer. Cover and steam the cake, replenishing water as needed, until the cake is firm, about 3 hours. Uncover the steamer, transfer the cake to a rack, and let cool until cake can be handled. Slice the cake into wedges and serve. half then cut each half crosswise into 1⁄2-inch-thick slabs.
For leftover cake, cool completely, then cut into 1⁄2-inch-thick slabs. In a large nonstick skillet, warm the remaining 3 tablespoons oil over medium-high heat. Working in batches, dredge the cake slices in the egg and cook, flipping once, until golden brown on both sides, about 1 1⁄2 minutes. Transfer the slices to a serving platter, sprinkle with sesame seeds, and serve while hot.